Achievement in mathematics through self-directed learning facilitation: an impact evaluation of an offline technological approach
- Authors: Zinn, Paméla Olive
- Date: 2024-12
- Subjects: Mathematics -- Study and teaching (Secondary) -- South Africa , Mathematical ability , Academic achievement -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68385 , vital:76992
- Description: International assessments indicate that mathematics education in South Africa is still in a crisis of significant proportions. This is reflected in the low pass rate of Grade 12 mathematics learners in South Africa in general, and in the Eastern Cape Province in particular. In response, the Govan Mbeki Mathematics Development Center (GMMDC) of the Nelson Mandela University (NMU) in the Eastern Cape developed an intervention strategy. A Techno-Blended support Model for teaching and learning mathematics (TBM), used as an intervention strategy, provides learners with potential from disadvantaged communities and under-resourced schools with 21st-century education technology. The defining features of the strategy which distinguishes it from others are that it is technology-enhanced, providing the learner access to mathematics teaching and learning without the need for Internet connectivity, that is, offline, incorporating blended learning into the approach. This ex-post study, using secondary analysis, evaluates the impact of the defining features of the strategy on learners' self-directed learning skills acquisition or enhancement for mathematics learning. Firstly, statistical analysis of secondary qualitative and quantitative data in a mixed methods approach, with primary qualitative data integrated into the secondary qualitative data employing quantification, is undertaken. The quantified data is then compared with the quantitative data (methodologic triangulation technique). Secondly, the theory-based Contribution Analysis is undertaken to increase the validity and credibility of the findings of the statistical analysis, providing an additional layer of triangulation. The study revealed that providing 21st-century digital education technology for use offline, within a blended learning environment, leads to a significant improvement in learner mathematics knowledge; conceptual understanding; positive self-perceptions; and finally, to the required intrinsic motivation to learn. Analysed data, obtained from the original study, indicates a positive correlation between learners who participated in the intervention strategy and enrolment in STEM-related courses at tertiary institutes. , Thesis (DPhil) -- Faculty of Education, School of Postgraduate education, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Zinn, Paméla Olive
- Date: 2024-12
- Subjects: Mathematics -- Study and teaching (Secondary) -- South Africa , Mathematical ability , Academic achievement -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68385 , vital:76992
- Description: International assessments indicate that mathematics education in South Africa is still in a crisis of significant proportions. This is reflected in the low pass rate of Grade 12 mathematics learners in South Africa in general, and in the Eastern Cape Province in particular. In response, the Govan Mbeki Mathematics Development Center (GMMDC) of the Nelson Mandela University (NMU) in the Eastern Cape developed an intervention strategy. A Techno-Blended support Model for teaching and learning mathematics (TBM), used as an intervention strategy, provides learners with potential from disadvantaged communities and under-resourced schools with 21st-century education technology. The defining features of the strategy which distinguishes it from others are that it is technology-enhanced, providing the learner access to mathematics teaching and learning without the need for Internet connectivity, that is, offline, incorporating blended learning into the approach. This ex-post study, using secondary analysis, evaluates the impact of the defining features of the strategy on learners' self-directed learning skills acquisition or enhancement for mathematics learning. Firstly, statistical analysis of secondary qualitative and quantitative data in a mixed methods approach, with primary qualitative data integrated into the secondary qualitative data employing quantification, is undertaken. The quantified data is then compared with the quantitative data (methodologic triangulation technique). Secondly, the theory-based Contribution Analysis is undertaken to increase the validity and credibility of the findings of the statistical analysis, providing an additional layer of triangulation. The study revealed that providing 21st-century digital education technology for use offline, within a blended learning environment, leads to a significant improvement in learner mathematics knowledge; conceptual understanding; positive self-perceptions; and finally, to the required intrinsic motivation to learn. Analysed data, obtained from the original study, indicates a positive correlation between learners who participated in the intervention strategy and enrolment in STEM-related courses at tertiary institutes. , Thesis (DPhil) -- Faculty of Education, School of Postgraduate education, 2024
- Full Text:
- Date Issued: 2024-12
Exploring children’s understandings of gender using critical literacy in a reading club
- Jansen, Lincoln Lee, Surname, name
- Authors: Jansen, Lincoln Lee , Surname, name
- Date: 2024-12
- Subjects: Book clubs (Discussion groups) -- South Africa , Literacy -- Study and teaching (Elementary) , Literacy -- Study and teaching (Middle school)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68333 , vital:76976
- Description: School literacy practices have always favoured traditional, gender stereotypical portrayals of characters in books. These portrayals are not troublesome as it helps children build a sense of identity. However, these portrayals often fail to represent people in more diverse ways and thus does not reflect how societies have progressed. These narrow portrayals are also often limiting and do not take into consideration people’s personal interests which can lead to them being ostracised and marginalised. The People’s Republic of China is the context for this study where traditional, conservative views are upheld about ways of being and doing for males and females. This is a qualitative study within the interpretivist paradigm which recognised the individual perceptions of participants within their specific sociocultural context. By establishing a reading club as a Third Space for literacy engagement, this study sought to explore how grade 2 learners at a school in Beijing, China responded to traditional and diverse portrayals of characters in books. This study regarded the establishment of a reading club as an empowering practice as it allowed a safe space for the participants to freely share their deliberations about ways of being in the world. Coupled with critical literacy as a practice, participants took a critical stance in instances of gender bias and injustices and in doing so, allowed them to accentuate their morality. Findings of this study suggest that the Chinese participants had very flexible ideas about ways of being and doing in the world as long as these did not conflict with their understandings of the law. Participants also upheld that gender performances and gendered behaviour are open to all with impunity. The findings of this study also highlight the importance of providing diverse literature to children as this helps them to deal with, and examine, issues they might not ordinarily encounter in a safe way and in doing so, expand their worldviews and cultivate empathy. , Thesis (PhD) -- Faculty of Education, School of Primary Schooling, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Jansen, Lincoln Lee , Surname, name
- Date: 2024-12
- Subjects: Book clubs (Discussion groups) -- South Africa , Literacy -- Study and teaching (Elementary) , Literacy -- Study and teaching (Middle school)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68333 , vital:76976
- Description: School literacy practices have always favoured traditional, gender stereotypical portrayals of characters in books. These portrayals are not troublesome as it helps children build a sense of identity. However, these portrayals often fail to represent people in more diverse ways and thus does not reflect how societies have progressed. These narrow portrayals are also often limiting and do not take into consideration people’s personal interests which can lead to them being ostracised and marginalised. The People’s Republic of China is the context for this study where traditional, conservative views are upheld about ways of being and doing for males and females. This is a qualitative study within the interpretivist paradigm which recognised the individual perceptions of participants within their specific sociocultural context. By establishing a reading club as a Third Space for literacy engagement, this study sought to explore how grade 2 learners at a school in Beijing, China responded to traditional and diverse portrayals of characters in books. This study regarded the establishment of a reading club as an empowering practice as it allowed a safe space for the participants to freely share their deliberations about ways of being in the world. Coupled with critical literacy as a practice, participants took a critical stance in instances of gender bias and injustices and in doing so, allowed them to accentuate their morality. Findings of this study suggest that the Chinese participants had very flexible ideas about ways of being and doing in the world as long as these did not conflict with their understandings of the law. Participants also upheld that gender performances and gendered behaviour are open to all with impunity. The findings of this study also highlight the importance of providing diverse literature to children as this helps them to deal with, and examine, issues they might not ordinarily encounter in a safe way and in doing so, expand their worldviews and cultivate empathy. , Thesis (PhD) -- Faculty of Education, School of Primary Schooling, 2024
- Full Text:
- Date Issued: 2024-12
Prevalence and correlates of sickness presenteeism among secondary school teachers in the Bukedi region of eastern Uganda
- Authors: Majwala,Henry
- Date: 2024-12
- Subjects: Employees -- Mental health , Psychology, Industrial , Industrial psychiatry
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68355 , vital:76989
- Description: Education is regarded as one of the main cornerstones for sustainable development, especially if the majority of the global citizenry manage to achieve it at secondary school level. The efficaciousness thereof, however, almost entirely depends on the productivity and performance of teachers meant to instill various skill sets among secondary school learners. Sickness presenteeism among secondary school teachers has previously emerged and gained attention as the single most important antagonist of secondary school productivity. However, it has been reported to be increasing in magnitude as absenteeism has gradually decreased over the years. The aim of the study was to establish the prevalence and correlates of sickness presenteeism among secondary school teachers in the Bukedi region in Eastern Uganda. The study adopted a pragmatic philosophy and a sequential explanatory mixed methods design targeting 433 secondary school teachers in the Bukedi sub region of Eastern Uganda. The schools were stratified by district first and then each district was stratified by ownership. Simple random sampling was used to sample half the number of schools per stratum, simple random sampling was used to sample the teachers. Key informants such as principals and teachers were purposively sampled and engaged in key informant semi-structured interviews. Quantitative data emerging from an analysis of the questionnaires was analyzed in SPSS version 25 using the log-binomial model, while the qualitative data from the semi-structured interviews was analyzed thematically. This study disclosed that the majority (68.3%) of the teachers engaged in sickness presenteeism. Moon lighting, egocentrism and heavy workload were the significant intrapersonal correlates of sickness presenteeism, while under staffing was a prominent institutional correlate. This study confirms findings from global research that staff working in people-based service sectors are most likely to engage in sickness presenteeism. The recommendations include the following: MoES to formulate a comprehensive policy on sickness presenteeism for teachers, DEOs to make follow ups to address the prevalent sickness presenteeism among secondary school teachers, the school administration to set up a special committee dealing with teachers’ welfare regarding ill health and work, and teachers are to be educated, sensitized about the dangers associated with sickness presenteeism and how to handle it with the school administration. , Thesis (DPhil) -- Faculty of Education, School of Post Schooling, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Majwala,Henry
- Date: 2024-12
- Subjects: Employees -- Mental health , Psychology, Industrial , Industrial psychiatry
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68355 , vital:76989
- Description: Education is regarded as one of the main cornerstones for sustainable development, especially if the majority of the global citizenry manage to achieve it at secondary school level. The efficaciousness thereof, however, almost entirely depends on the productivity and performance of teachers meant to instill various skill sets among secondary school learners. Sickness presenteeism among secondary school teachers has previously emerged and gained attention as the single most important antagonist of secondary school productivity. However, it has been reported to be increasing in magnitude as absenteeism has gradually decreased over the years. The aim of the study was to establish the prevalence and correlates of sickness presenteeism among secondary school teachers in the Bukedi region in Eastern Uganda. The study adopted a pragmatic philosophy and a sequential explanatory mixed methods design targeting 433 secondary school teachers in the Bukedi sub region of Eastern Uganda. The schools were stratified by district first and then each district was stratified by ownership. Simple random sampling was used to sample half the number of schools per stratum, simple random sampling was used to sample the teachers. Key informants such as principals and teachers were purposively sampled and engaged in key informant semi-structured interviews. Quantitative data emerging from an analysis of the questionnaires was analyzed in SPSS version 25 using the log-binomial model, while the qualitative data from the semi-structured interviews was analyzed thematically. This study disclosed that the majority (68.3%) of the teachers engaged in sickness presenteeism. Moon lighting, egocentrism and heavy workload were the significant intrapersonal correlates of sickness presenteeism, while under staffing was a prominent institutional correlate. This study confirms findings from global research that staff working in people-based service sectors are most likely to engage in sickness presenteeism. The recommendations include the following: MoES to formulate a comprehensive policy on sickness presenteeism for teachers, DEOs to make follow ups to address the prevalent sickness presenteeism among secondary school teachers, the school administration to set up a special committee dealing with teachers’ welfare regarding ill health and work, and teachers are to be educated, sensitized about the dangers associated with sickness presenteeism and how to handle it with the school administration. , Thesis (DPhil) -- Faculty of Education, School of Post Schooling, 2024
- Full Text:
- Date Issued: 2024-12
The lived experiences of final-year undergraduate diagnostic radiography students applying radiation protection measures during clinical practice
- Authors: Campbell, Sydney Samuel
- Date: 2024-12
- Subjects: Radiographers , College students -- South Africa , Experiential learning
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68311 , vital:76973
- Description: Radiographers use ionising radiation to produce radiographic images and the use of ionising radiation in healthcare has both benefits and risks for patients and healthcare professionals. It is therefore important that radiographers mitigate the risks associated with ionising radiation. It is for this reason that radiation protection measures are applied to ensure the safety of patients, staff, and the public. Furthermore, radiographers are also responsible for mentoring radiography students and inculcate the use of radiation protection measures when students undergo their workplace learning. This mentoring takes place in the clinical setting with its characteristics that may or may not advance the application of radiation protection measures. The aim of this study was to investigate the lived experiences of final-year undergraduate radiography students applying radiation protection measures in the clinical setting and to propose strategies to foster the integration of radiation protection theory into clinical practice. This study was located in the interpretivist paradigm using phenomenology as a research method and theoretical framework to achieve the stated aim. The target population for this qualitative study included all registered final-year undergraduate radiography students at the local university who perform their WPL at the accredited training hospitals in the Eastern Cape Province as this cohort of students have more clinical experience than the first-, second- and third-year students. The target population comprised 28 students. Purposive sampling was employed to select the group of radiography students to interview. The study used phenomenological interviews as a data collection tool and the collected data was explicated using a self-developed method. The trustworthiness of the study was ensured by applying Guba’s model of trustworthiness that includes credibility, transferability, confirmability, dependability and authenticity and was further enhanced by reflecting on the balanced integration, openness, concreteness, and resonance of the study. This study employed an ethical framework referred to as principlism that includes the notions of autonomy, beneficence, non-maleficence and justice.Data explication was conducted using three cycles of explication. Cycle one produced interpretive profiles for each participant. The interpretive profiles revealed the life histories of each participant as well as the utterances of participants related to the three sub-questions. Cycle two produced four themes. Theme one described participants’ being with others such as radiographers, clinical supervisors, medical doctors, and patients and revealed the tension between participants’ belonging and being unwanted. Theme two characterised the clinical setting as a place where several factors flow together to provide participants with their individualised experiences. Theme two revealed the emotional distress; the learning through trial-and-error; the independent learning; learning that is coupled with humiliation as experienced by participants. The clinical space was also characterised as a place to be survived, a place where students have to be inconspicuous and understand the acceptable levels of engagement with others. It is also a place where theory and practice at times is in alignment at other times not in alignment. The clinical setting could also be a place of self-doubt and insecurity, a place of personal growth, and a place where historical events are significant. Theme three disclosed the unspoken lessons that were conveyed through the actions and behaviours of individuals in the clinical environment. Unintended lesson one is that radiation protection measures are not important. Lesson two suggest that classroom teaching about radiation protection is not valid in the clinical setting, and finally that incivility towards radiography students is acceptable. Theme four revealed the difficulties experienced by radiography students when navigating ethical dilemmas. The theme revealed radiographers’ and radiologists’ indifference towards radiation protection, the non-application of radiation protection measures, and the inconsistency and apathy towards radiation protection measures. Cycle three viewed the experiences of participants through the lens of Dasein’s disclosedness. This revealed the exclusive language used by participants, the largely negative mood and participants’ disconnection from the imaging department.Finally, the study presented new and important insights by probing the topic of radiation protection in a novel way by using phenomenology to focus on the lived experiences of final-year undergraduate students applying radiation protection measures in the clinical setting. The findings of the study also allowed for the development of Enhancement strategies that could be used by institutions of higher education to promote the integration of the theory and practice of radiation protection measures in the clinical setting. It is recommended, though, that a study that includes all South African institutions of higher learning offering radiography be conducted using phenomenology. Furthermore, the views of South African radiographers and clinical supervisors should also be elicited to corroborate the views of participants in this study. , Thesis (PhD) -- Faculty of Education, School of Secondary Education, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Campbell, Sydney Samuel
- Date: 2024-12
- Subjects: Radiographers , College students -- South Africa , Experiential learning
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68311 , vital:76973
- Description: Radiographers use ionising radiation to produce radiographic images and the use of ionising radiation in healthcare has both benefits and risks for patients and healthcare professionals. It is therefore important that radiographers mitigate the risks associated with ionising radiation. It is for this reason that radiation protection measures are applied to ensure the safety of patients, staff, and the public. Furthermore, radiographers are also responsible for mentoring radiography students and inculcate the use of radiation protection measures when students undergo their workplace learning. This mentoring takes place in the clinical setting with its characteristics that may or may not advance the application of radiation protection measures. The aim of this study was to investigate the lived experiences of final-year undergraduate radiography students applying radiation protection measures in the clinical setting and to propose strategies to foster the integration of radiation protection theory into clinical practice. This study was located in the interpretivist paradigm using phenomenology as a research method and theoretical framework to achieve the stated aim. The target population for this qualitative study included all registered final-year undergraduate radiography students at the local university who perform their WPL at the accredited training hospitals in the Eastern Cape Province as this cohort of students have more clinical experience than the first-, second- and third-year students. The target population comprised 28 students. Purposive sampling was employed to select the group of radiography students to interview. The study used phenomenological interviews as a data collection tool and the collected data was explicated using a self-developed method. The trustworthiness of the study was ensured by applying Guba’s model of trustworthiness that includes credibility, transferability, confirmability, dependability and authenticity and was further enhanced by reflecting on the balanced integration, openness, concreteness, and resonance of the study. This study employed an ethical framework referred to as principlism that includes the notions of autonomy, beneficence, non-maleficence and justice.Data explication was conducted using three cycles of explication. Cycle one produced interpretive profiles for each participant. The interpretive profiles revealed the life histories of each participant as well as the utterances of participants related to the three sub-questions. Cycle two produced four themes. Theme one described participants’ being with others such as radiographers, clinical supervisors, medical doctors, and patients and revealed the tension between participants’ belonging and being unwanted. Theme two characterised the clinical setting as a place where several factors flow together to provide participants with their individualised experiences. Theme two revealed the emotional distress; the learning through trial-and-error; the independent learning; learning that is coupled with humiliation as experienced by participants. The clinical space was also characterised as a place to be survived, a place where students have to be inconspicuous and understand the acceptable levels of engagement with others. It is also a place where theory and practice at times is in alignment at other times not in alignment. The clinical setting could also be a place of self-doubt and insecurity, a place of personal growth, and a place where historical events are significant. Theme three disclosed the unspoken lessons that were conveyed through the actions and behaviours of individuals in the clinical environment. Unintended lesson one is that radiation protection measures are not important. Lesson two suggest that classroom teaching about radiation protection is not valid in the clinical setting, and finally that incivility towards radiography students is acceptable. Theme four revealed the difficulties experienced by radiography students when navigating ethical dilemmas. The theme revealed radiographers’ and radiologists’ indifference towards radiation protection, the non-application of radiation protection measures, and the inconsistency and apathy towards radiation protection measures. Cycle three viewed the experiences of participants through the lens of Dasein’s disclosedness. This revealed the exclusive language used by participants, the largely negative mood and participants’ disconnection from the imaging department.Finally, the study presented new and important insights by probing the topic of radiation protection in a novel way by using phenomenology to focus on the lived experiences of final-year undergraduate students applying radiation protection measures in the clinical setting. The findings of the study also allowed for the development of Enhancement strategies that could be used by institutions of higher education to promote the integration of the theory and practice of radiation protection measures in the clinical setting. It is recommended, though, that a study that includes all South African institutions of higher learning offering radiography be conducted using phenomenology. Furthermore, the views of South African radiographers and clinical supervisors should also be elicited to corroborate the views of participants in this study. , Thesis (PhD) -- Faculty of Education, School of Secondary Education, 2024
- Full Text:
- Date Issued: 2024-12
Vocational Education and the relentless struggles of TVET graduates in the Eastern Cape, South Africa: A Freirean approach
- Authors: Majola, Ezekiel
- Date: 2024-12
- Subjects: Vocational education -- Eastern Cape -- South Africa , Technical education -- Eastern Cape -- South Africa , School-to-work transition -- Eastern Cape -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/${Handle} , vital:76985
- Description: This study employs Paulo Freire’s framework to contribute to debates surrounding social justice and transformation in vocational education and training (TVET). By offering a critical perspective on dominant discourse and practices, it challenges prevailing trajectories of powerful knowledge and inherent assumptions and biases in TVET. Drawing on a Freirean framework, the research provides insights to develop more equitable and transformative practices by addressing power, privilege, and social inequality in TVET. Through dialogue and collaboration with students, it promotes critical consciousness and relevant skills and knowledge. Highlighting the significance of context, it underscores the need to understand the social and cultural context of learning. Demonstrating the potential of a Freirean framework to challenge the status quo, it promotes more equitable and empowering practices in TVET. The chosen methodology for this study is Participatory Action Research (PAR), integrating theory, action, and participation to address social issues. Recruiting 15 NC(V) graduates from Algoa TVET College, forming a Learning Cycle Group (LCG), the study aimed to comprehend graduates’ experiences, challenges, and opportunities. Life narrative interviews and LCG meetings generated data, ensuring every participant had a voice and strengthening group cohesion. Data were grounded in ethical values such as respect, equality, inclusion, democratic participation, active learning, making a difference, collective action, and personal integrity. Employing Paulo Freire’s theoretical framework, this study offers a novel perspective on TVET in South Africa, fostering dialogue with TVET students to challenge conventional discourses. It aimed to develop an alternative conceptualisation of TVET by incorporating student experiences and perspectives, promoting positive change through dialogue and addressing power dynamics and social justice issues. The study explores Powell’s (2014) question regarding TVET colleges’ role in expanding opportunities for students and asks: “How do TVET graduates experience life after graduation? Are they empowered and satisfied with their social status?” Sub-questions inquire about students’ expectations upon enrolling, opportunities after completing NC(V) programs, and the extent to which TVET colleges address unemployment and socio-economic injustices, aiming to inspire the development of praxis and frameworks that better serve the needs of TVET graduates and address social concerns.The study’s findings, analysed through Freire’s ideology in “We Make the Road by Walking” (1990) and “Pedagogy of Hope” (1994), reveal that the NC(V) program predominantly attracts underprivileged students and is rarely their first choice. This research highlights that the NC(V) program does not fully empower or transform students’ circumstances, instead perpetuating cycles of poverty, unemployment, and social inequality—contrary to Freire’s vision of education as a tool for liberation and societal change. The program fails to provide meaningful employment opportunities, leaving graduates often unemployed or in low-paying jobs, unable to escape poverty. This underscores the program’s inadequacies. Furthermore, insufficient support structures and practical application opportunities further diminish graduates’ employability. The study’s findings emphasise the need for systemic reforms in the NC(V) program. Embracing Freire’s principles and moving beyond traditional banking education models to more inclusive, participatory approaches is essential. This transformation is crucial for the TVET system to genuinely empower students and foster significant personal and societal change. , Thesis (PhD) -- Faculty of Education, School of Secondary School Education, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Majola, Ezekiel
- Date: 2024-12
- Subjects: Vocational education -- Eastern Cape -- South Africa , Technical education -- Eastern Cape -- South Africa , School-to-work transition -- Eastern Cape -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/${Handle} , vital:76985
- Description: This study employs Paulo Freire’s framework to contribute to debates surrounding social justice and transformation in vocational education and training (TVET). By offering a critical perspective on dominant discourse and practices, it challenges prevailing trajectories of powerful knowledge and inherent assumptions and biases in TVET. Drawing on a Freirean framework, the research provides insights to develop more equitable and transformative practices by addressing power, privilege, and social inequality in TVET. Through dialogue and collaboration with students, it promotes critical consciousness and relevant skills and knowledge. Highlighting the significance of context, it underscores the need to understand the social and cultural context of learning. Demonstrating the potential of a Freirean framework to challenge the status quo, it promotes more equitable and empowering practices in TVET. The chosen methodology for this study is Participatory Action Research (PAR), integrating theory, action, and participation to address social issues. Recruiting 15 NC(V) graduates from Algoa TVET College, forming a Learning Cycle Group (LCG), the study aimed to comprehend graduates’ experiences, challenges, and opportunities. Life narrative interviews and LCG meetings generated data, ensuring every participant had a voice and strengthening group cohesion. Data were grounded in ethical values such as respect, equality, inclusion, democratic participation, active learning, making a difference, collective action, and personal integrity. Employing Paulo Freire’s theoretical framework, this study offers a novel perspective on TVET in South Africa, fostering dialogue with TVET students to challenge conventional discourses. It aimed to develop an alternative conceptualisation of TVET by incorporating student experiences and perspectives, promoting positive change through dialogue and addressing power dynamics and social justice issues. The study explores Powell’s (2014) question regarding TVET colleges’ role in expanding opportunities for students and asks: “How do TVET graduates experience life after graduation? Are they empowered and satisfied with their social status?” Sub-questions inquire about students’ expectations upon enrolling, opportunities after completing NC(V) programs, and the extent to which TVET colleges address unemployment and socio-economic injustices, aiming to inspire the development of praxis and frameworks that better serve the needs of TVET graduates and address social concerns.The study’s findings, analysed through Freire’s ideology in “We Make the Road by Walking” (1990) and “Pedagogy of Hope” (1994), reveal that the NC(V) program predominantly attracts underprivileged students and is rarely their first choice. This research highlights that the NC(V) program does not fully empower or transform students’ circumstances, instead perpetuating cycles of poverty, unemployment, and social inequality—contrary to Freire’s vision of education as a tool for liberation and societal change. The program fails to provide meaningful employment opportunities, leaving graduates often unemployed or in low-paying jobs, unable to escape poverty. This underscores the program’s inadequacies. Furthermore, insufficient support structures and practical application opportunities further diminish graduates’ employability. The study’s findings emphasise the need for systemic reforms in the NC(V) program. Embracing Freire’s principles and moving beyond traditional banking education models to more inclusive, participatory approaches is essential. This transformation is crucial for the TVET system to genuinely empower students and foster significant personal and societal change. , Thesis (PhD) -- Faculty of Education, School of Secondary School Education, 2024
- Full Text:
- Date Issued: 2024-12
(In)security communities in Africa: small arms and light weapons norm compliance by the economic community of West African states
- Authors: Pokoo, John Mark
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/467093 , vital:76814
- Description: Access restricted. Expected release in 2026. , Thesis (PhD) -- Faculty of Humanities, Political and International Studies, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Pokoo, John Mark
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/467093 , vital:76814
- Description: Access restricted. Expected release in 2026. , Thesis (PhD) -- Faculty of Humanities, Political and International Studies, 2024
- Full Text:
- Date Issued: 2024-10-11
A case study of GADRA’s community-engaged praxis for educational transformation
- Authors: Msomi, Nqobile Nomonde
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/464864 , vital:76552 , DOI https://doi.org/10.21504/10962/464864
- Description: Although South Africa has achieved considerable steps in development over the last thirty years, post-apartheid South Africa is characterised by widespread poverty, high unemployment and systemic inequality. According to the country’s National Planning Commission, education is central to achieving the overarching democratic goals of eliminating poverty and reducing inequality. This positions education as an important site for the liberation and well-being of our country’s majority. This case study takes a community psychology perspective on education; more specifically the education-development nexus wherein Non-Governmental Organisations (NGOs) are centrally positioned. NGOs are contentiously positioned in the development discourse. Nonetheless, they have played a key role with regards to siding with the poor, the excluded, persistently marginalised and oppressed majority and to bringing about social justice, following South Africa’s colonial and apartheid histories, as well as in the current democratic dispensation. This study situates a local NGO, GADRA Education, within the country’s socio-political and educational landscape. Founded in the 1950s and located in Makhanda, it has been operating in the rural Eastern Cape province for more than sixty years. In the present-day, GADRA Education positions itself at the centre of a dense network of education institutions in Makhanda, including Rhodes University, and collaborates with a number of education stakeholders in the small city. The case study consisted of two consecutive phases: a Foucauldian discourse analysis of GADRA’s annual reports between 2012 and 2021, followed by individual narrative interviews with 13 organisational members. An Africa(n)-centred community psychology orientation, revealed counter-discourse to the national “crisis in education” discourse surrounding the NGO. The discourse of crisis produced the legitimation for GADRA Education’s continued existence, action and embeddedness in Makhanda. The discourse of transformation informed their modes of support across primary, secondary and higher education. The discourse of access and participation constructed the NGO as a bridge and link between phases of education. The discourse of collaborative partnerships enabled solidarity between state and non-state actors towards educational change. Finally, the discourse of development positioned development at a grassroots level. These constellations formed GADRA Education’s counter-discourse, which produced the Organisation’s apparatus of resistance, formulated as situated praxis. The 5 organisational members’ narratives revealed the apparatus’s impacts on the subjectivities of youth in Makhanda in engendering hope and driving educational change in the city. In contrast to conceptions of education NGOs who work in the public schooling sector making little progress in dismantling educational inequity, this study illustrates the techniques of resistance leveraged, in the context of collaborative partnerships, by the local NGO. These techniques have wider applicability for education-development practitioners concerned with transformative change in their educational locales. It illustrates the principles and modes by which NGOs can operate in solidarity with the persistently marginalised majority, and thus contribute to shaping our imagined educational futures. I argue that psychology is a useful site to think about justice. Critical psychological theory can enable a deeper understanding of practice that contributes to impactful community organisation, intervention and resistance in the country’s education sector. The operationalisation of the values and principles of community psychology can make important contributions at the nexus of theory and practice in working towards educational, and ultimately social, change. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Msomi, Nqobile Nomonde
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/464864 , vital:76552 , DOI https://doi.org/10.21504/10962/464864
- Description: Although South Africa has achieved considerable steps in development over the last thirty years, post-apartheid South Africa is characterised by widespread poverty, high unemployment and systemic inequality. According to the country’s National Planning Commission, education is central to achieving the overarching democratic goals of eliminating poverty and reducing inequality. This positions education as an important site for the liberation and well-being of our country’s majority. This case study takes a community psychology perspective on education; more specifically the education-development nexus wherein Non-Governmental Organisations (NGOs) are centrally positioned. NGOs are contentiously positioned in the development discourse. Nonetheless, they have played a key role with regards to siding with the poor, the excluded, persistently marginalised and oppressed majority and to bringing about social justice, following South Africa’s colonial and apartheid histories, as well as in the current democratic dispensation. This study situates a local NGO, GADRA Education, within the country’s socio-political and educational landscape. Founded in the 1950s and located in Makhanda, it has been operating in the rural Eastern Cape province for more than sixty years. In the present-day, GADRA Education positions itself at the centre of a dense network of education institutions in Makhanda, including Rhodes University, and collaborates with a number of education stakeholders in the small city. The case study consisted of two consecutive phases: a Foucauldian discourse analysis of GADRA’s annual reports between 2012 and 2021, followed by individual narrative interviews with 13 organisational members. An Africa(n)-centred community psychology orientation, revealed counter-discourse to the national “crisis in education” discourse surrounding the NGO. The discourse of crisis produced the legitimation for GADRA Education’s continued existence, action and embeddedness in Makhanda. The discourse of transformation informed their modes of support across primary, secondary and higher education. The discourse of access and participation constructed the NGO as a bridge and link between phases of education. The discourse of collaborative partnerships enabled solidarity between state and non-state actors towards educational change. Finally, the discourse of development positioned development at a grassroots level. These constellations formed GADRA Education’s counter-discourse, which produced the Organisation’s apparatus of resistance, formulated as situated praxis. The 5 organisational members’ narratives revealed the apparatus’s impacts on the subjectivities of youth in Makhanda in engendering hope and driving educational change in the city. In contrast to conceptions of education NGOs who work in the public schooling sector making little progress in dismantling educational inequity, this study illustrates the techniques of resistance leveraged, in the context of collaborative partnerships, by the local NGO. These techniques have wider applicability for education-development practitioners concerned with transformative change in their educational locales. It illustrates the principles and modes by which NGOs can operate in solidarity with the persistently marginalised majority, and thus contribute to shaping our imagined educational futures. I argue that psychology is a useful site to think about justice. Critical psychological theory can enable a deeper understanding of practice that contributes to impactful community organisation, intervention and resistance in the country’s education sector. The operationalisation of the values and principles of community psychology can make important contributions at the nexus of theory and practice in working towards educational, and ultimately social, change. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2024
- Full Text:
- Date Issued: 2024-10-11
A conspiracy of silence: the authorial potential of full masks in performer training, dramaturgy and audience perception in South African visual theatre
- Authors: Murray, Robert Ian
- Date: 2024-10-11
- Subjects: Liezl de Kock , People with disabilities and the performing arts , Experimental theater South Africa , Actors Training of , Theater for deaf people South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/467083 , vital:76813 , DOI https://doi.org/10.21504/10962/467083
- Description: Silent Mask Theatre in South Africa has the potential to cut across linguistic divides and deliver a product that offers an intimate, unique experience for the audience as well as the actor. South Africa not only has a complicated history, but also 11 languages (12 if one counts South African Sign Language – SASL -, which still holds a curious position of being counted official or not), and the one that theatre-makers choose to present in gives a certain “authority” to the production. Silent masks remove the need for linguistic understanding, something necessary for more abstract thought, and focusses instead on the emotional relevance and interplay between characters. In doing so, it proves an important way to create relevance for an audience, creating a delicate dance between the Mask (character and thereby text), how the actor plays it, and then the closing of meaning through the audience experience. Thus, is created a trialogue between these elements that gives the production the opportunity to speak to the hearts and minds of the audience. Globally, the study of silent character masks is still relatively new, with proponents of it only coming to the fore in the past few years (Wilsher, 2007). Mask Theatre has grown exponentially in the UK and Europe with companies like Vamos Theatre, exploring PTSD in works like A Brave Face (2018) or death in Dead Good (2021), and Familie Flöz either on the more whimsical side like Hotel Paradiso (2011) or the more hard-hitting Infinito (2006), gaining popularity and exposure. In South Africa, there is strangely not an indigenous tradition of masks, as opposed to other parts of Africa. This is fascinating, and probably points towards a more “oral tradition” of South Africa/Africa. However, the author aims to point out the ways that the silent mask entered South African consciousness at a time where more attention was being paid to “performing objects” (Proschan, 1985), and particularly in Cape Town with the advent of the Out the Box Festival. This thesis aims to contextualise Visual Theatre and Mask Theatre in a South African context, seeing within it a movement towards a more global perspective of puppetry, material performances, and performing objects. Although “ghettoised” for a long time (Taylor, 2004), performing objects emerged and became a leading case for the primal “text” of a performance. Handspring Puppet Company, Janni Younge, and the author’s company, FTH:K, became primary grounds of contestation against more conventional, text-based theatre. Starting with a reflective account of the author’s journey towards masks, the thesis branches out into a reflection on its author’s pedagogical praxis, and how silent masks work, before critically reflecting on and analysing his key works, such as Pictures of You (2008-2013), which deals with home invasions and grief, and Benchmarks (2011), which deals with the wave of xenophobia that hit South Africa around that time. . This were built from the ground up, working with current issues both in the author’s, and the country’s, mileau. In the last two decades, performing object work in South Africa has begun to flourish. This is the first thesis to investigate mask work in the country during this period. Its possibilities for Screen and Stage Acting are still being explored. , Thesis (PhD) -- Faculty of Humanities, Drama, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Murray, Robert Ian
- Date: 2024-10-11
- Subjects: Liezl de Kock , People with disabilities and the performing arts , Experimental theater South Africa , Actors Training of , Theater for deaf people South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/467083 , vital:76813 , DOI https://doi.org/10.21504/10962/467083
- Description: Silent Mask Theatre in South Africa has the potential to cut across linguistic divides and deliver a product that offers an intimate, unique experience for the audience as well as the actor. South Africa not only has a complicated history, but also 11 languages (12 if one counts South African Sign Language – SASL -, which still holds a curious position of being counted official or not), and the one that theatre-makers choose to present in gives a certain “authority” to the production. Silent masks remove the need for linguistic understanding, something necessary for more abstract thought, and focusses instead on the emotional relevance and interplay between characters. In doing so, it proves an important way to create relevance for an audience, creating a delicate dance between the Mask (character and thereby text), how the actor plays it, and then the closing of meaning through the audience experience. Thus, is created a trialogue between these elements that gives the production the opportunity to speak to the hearts and minds of the audience. Globally, the study of silent character masks is still relatively new, with proponents of it only coming to the fore in the past few years (Wilsher, 2007). Mask Theatre has grown exponentially in the UK and Europe with companies like Vamos Theatre, exploring PTSD in works like A Brave Face (2018) or death in Dead Good (2021), and Familie Flöz either on the more whimsical side like Hotel Paradiso (2011) or the more hard-hitting Infinito (2006), gaining popularity and exposure. In South Africa, there is strangely not an indigenous tradition of masks, as opposed to other parts of Africa. This is fascinating, and probably points towards a more “oral tradition” of South Africa/Africa. However, the author aims to point out the ways that the silent mask entered South African consciousness at a time where more attention was being paid to “performing objects” (Proschan, 1985), and particularly in Cape Town with the advent of the Out the Box Festival. This thesis aims to contextualise Visual Theatre and Mask Theatre in a South African context, seeing within it a movement towards a more global perspective of puppetry, material performances, and performing objects. Although “ghettoised” for a long time (Taylor, 2004), performing objects emerged and became a leading case for the primal “text” of a performance. Handspring Puppet Company, Janni Younge, and the author’s company, FTH:K, became primary grounds of contestation against more conventional, text-based theatre. Starting with a reflective account of the author’s journey towards masks, the thesis branches out into a reflection on its author’s pedagogical praxis, and how silent masks work, before critically reflecting on and analysing his key works, such as Pictures of You (2008-2013), which deals with home invasions and grief, and Benchmarks (2011), which deals with the wave of xenophobia that hit South Africa around that time. . This were built from the ground up, working with current issues both in the author’s, and the country’s, mileau. In the last two decades, performing object work in South Africa has begun to flourish. This is the first thesis to investigate mask work in the country during this period. Its possibilities for Screen and Stage Acting are still being explored. , Thesis (PhD) -- Faculty of Humanities, Drama, 2024
- Full Text:
- Date Issued: 2024-10-11
A house accursed: reconsidering Sophocles’ sisters, Antigone & Ismene
- Authors: Fox, Peta Ann , Sophocles
- Date: 2024-10-11
- Subjects: Ismene (Greek mythology) , Antigone (Greek mythological figure) , Electra (Greek mythological figure) , Chrysothemis , Greek tragedy , Sisters in literature
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/467028 , vital:76808 , DOI https://doi.org/10.21504/10962/467028
- Description: Traditionally, Ismene’s refusal to help Antigone bury their brother in Sophocles’ Antigone tends to be regarded only in relation to Antigone’s own remarkable bravery. Antigone exists on the heroic level, Ismene on the ordinary; Antigone is courageous, Ismene is timid and submissive; Antigone is an idealist and an individualist, Ismene is convention and herd-bound. Ismene is, in many ways, presented as the antithesis of Antigone and Sophocles does indeed make use of her character as a foil to Antigone, but this thesis will argue that the relation between the two sisters is far more complicated than a dichotomous contrast between ‘extraordinary heroine’ and ‘average woman’. Like Antigone, Ismene is very much a character in her own right, and her emotions, motivations and impulses are every bit as realised and compelling as Antigone’s own. Both sisters have been deeply affected by the tragic misfortunes of their family, but their sad history affects each sister quite differently. Whereas Antigone’s instinctive reaction to Creon’s edict is a furious determination not to tolerate any further dishonour, Ismene’s equally instinctive reaction is to avoid the pattern of self-destructive inwardness that has plagued their family for generations. By offering a comprehensive re-examination of the key passages that have informed our critical reception of Ismene and the nature of her relationship with Antigone, this study aims to disrupt the established, and largely prejudiced, reading of Ismene as a model of feminine timidity and submission. Although Ismene is certainly no grand tragic heroine, titling the theoretical focus away from the death-oriented extremism of Antigone towards a more balanced consideration of the so-called ‘weaker sister’ not only allows for new insights into the nature of Sophoclean tragedy, but also challenges the very basis on which Ismene has so often been dismissed in favour of her more intrepid sister: the pervasive assumption that Sophocles has only given us one sister who is willing to risk her life for a principle. , Thesis (PhD) -- Faculty of Humanities, School of Languages and Literatures, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Fox, Peta Ann , Sophocles
- Date: 2024-10-11
- Subjects: Ismene (Greek mythology) , Antigone (Greek mythological figure) , Electra (Greek mythological figure) , Chrysothemis , Greek tragedy , Sisters in literature
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/467028 , vital:76808 , DOI https://doi.org/10.21504/10962/467028
- Description: Traditionally, Ismene’s refusal to help Antigone bury their brother in Sophocles’ Antigone tends to be regarded only in relation to Antigone’s own remarkable bravery. Antigone exists on the heroic level, Ismene on the ordinary; Antigone is courageous, Ismene is timid and submissive; Antigone is an idealist and an individualist, Ismene is convention and herd-bound. Ismene is, in many ways, presented as the antithesis of Antigone and Sophocles does indeed make use of her character as a foil to Antigone, but this thesis will argue that the relation between the two sisters is far more complicated than a dichotomous contrast between ‘extraordinary heroine’ and ‘average woman’. Like Antigone, Ismene is very much a character in her own right, and her emotions, motivations and impulses are every bit as realised and compelling as Antigone’s own. Both sisters have been deeply affected by the tragic misfortunes of their family, but their sad history affects each sister quite differently. Whereas Antigone’s instinctive reaction to Creon’s edict is a furious determination not to tolerate any further dishonour, Ismene’s equally instinctive reaction is to avoid the pattern of self-destructive inwardness that has plagued their family for generations. By offering a comprehensive re-examination of the key passages that have informed our critical reception of Ismene and the nature of her relationship with Antigone, this study aims to disrupt the established, and largely prejudiced, reading of Ismene as a model of feminine timidity and submission. Although Ismene is certainly no grand tragic heroine, titling the theoretical focus away from the death-oriented extremism of Antigone towards a more balanced consideration of the so-called ‘weaker sister’ not only allows for new insights into the nature of Sophoclean tragedy, but also challenges the very basis on which Ismene has so often been dismissed in favour of her more intrepid sister: the pervasive assumption that Sophocles has only given us one sister who is willing to risk her life for a principle. , Thesis (PhD) -- Faculty of Humanities, School of Languages and Literatures, 2024
- Full Text:
- Date Issued: 2024-10-11
A mechanistic and trait-based approach to investigating macroinvertebrates distribution and exposure to microplastics in riverine systems
- Authors: Owowenu, Enahoro Kennedy
- Date: 2024-10-11
- Subjects: Microplastics Environmental aspects , Water quality biological assessment , Hydrodynamics , Hydrogeomorphology , Biotope , Flow type
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466666 , vital:76765 , DOI https://doi.org/10.21504/10962/466666
- Description: Microplastics in rivers pose an ecological risk. Hydraulic biotopes form distinct flow patches that vary longitudinally along the river, potentially influencing the transport dynamics of microplastics. Macroinvertebrates exhibit adaptations to different hydraulic biotopes through their unique traits. These traits can mediate their exposure to microplastics, thereby imposing selective pressures on these organisms. Different taxa often demonstrate preferences for specific hydraulic biotopes characterized by distinct flow regimes. Understanding the transport dynamics of microplastics mediated by hydraulic biotopes and the potential exposure of macroinvertebrates at the hydraulic biotope scale is important for determining the fate of riverine microplastics and detecting species at risk. Both empirical and theoretical studies have highlighted the interconnectedness of hydrology, geomorphology, and microplastic transport in rivers, yet, there remains a gap in understanding how a hydro-geomorphological approach could enhance the understanding of the microplastic transport process. Little is known about the role of traits in driving macroinvertebrate exposure to microplastics at a scale relevant to ecological dynamics. This study addressed these gaps by applying a hydro-geomorphological approach to investigate the distribution of microplastics at the hydraulic biotope scale and assessed the potential exposure of macroinvertebrates using a trait-based approach. This study also explored the relationship between microplastic abundance and selected water physicochemical properties, as well as the influence of adjacent land use types. By integrating these aspects the research provided a comprehensive understanding of microplastics dynamics in river systems, shedding light on both environmental factors shaping their distribution and the potential impacts on aquatic organisms. The study was conducted over the wet and dry seasons (October 2021 – July 2022) at 10 sites located in the upper, middle, and lower reaches of the Swartkops and Buffalo River systems in the Eastern Cape Province of South Africa. The hydraulic biotopes (i.e., pools, runs, riffles) were grouped into two conceptualised forms, namely, sink and flush hydraulic zones and were characterized by hydraulic indices such as the Froude number and the Reynolds number. The flush hydraulic zone represents hydraulic biotopes where microplastics can potentially be remobilized quickly into suspension, and the sink represents biotopes where microplastics can potentially accumulate and remobilisation is far slower. Fast-to-moderate flowing hydraulic biotopes were conceptualised as microplastics flush zones while slow-flowing to still biotopes as microplastic sink zones. Samples were collected at different depths in each hydraulic zone to quantify suspended and settled forms of microplastics. Microplastics targeted in this study ranged in size from 0.063 mm to less than 5 mm. Classification was achieved through microscopic observation, and confirmation via Fourier Transform Infrared Spectroscopy (FTIR-ATR) was conducted for samples ranging from 0.5 mm to less than 5 mm. At the site level, settled microplastics showed statistically significant spatial and temporal variations between the sites, and between the seasons (P < 0.05). The suspended microplastic varied only spatially. Fibres and fragments were the dominant microplastic shape, while polyethylene and polypropylene were the dominant microplastic polymers. Suspended microplastics showed statistically significant variation between urban land cover and other land cover categories (industrial, agricultural, rural, and natural land cover). Microplastics abundance was associated with high levels of turbidity, total suspended solids, total inorganic nitrogen, higher temperatures and increasing electrical conductivity. At the hydraulic biotope scale, the mean occurrence of suspended microplastics (1.76 ± 1.44 items/L; mean + SD) in the flush hydraulic zone was higher than that in the sink zone (1.54 ± 1.46 items/L), while settled microplastics were more abundant in the sink hydraulic zone (1.82 ± 1.98 items/L) than the flush hydraulic zone (1.32 ± 1.49 items/L). This observation was in line with the prediction in this study. The mean suspended and settled microplastics concentrations were higher during the wet season across the flush and sink hydraulic zones than in the dry season. Global multivariate analysis of variance (MANOVA) and two-way analysis of variance (ANOVA) revealed significant spatial and temporal variations in settled microplastics abundances between the flush and sink hydraulic zones. The results indicated that geomorphologically defined units such as riffles and moderate to fast runs (flush) generally contained lower amounts of settled microplastics compared to pools and backwaters (sink). However, this distinction between the flush and sink microplastic zones was observed only for settled microplastics and not for suspended microplastics. Suspended and settled microplastics showed a statistically significant relationship with the Froude number index. The generalised additive model indicated that settled microplastics abundance distribution decreased significantly with increasing Froude number value in the flush zone. Suspended microplastics decreased at low Froude number values and showed an increasing trend at higher Froude number values of about 0.75. The results indicate the usefulness of the hydraulic biotope scale microplastic monitoring approach in detecting microplastic hotspots and explaining variations in microplastics abundances driven by instream hydraulics. Four traits and ecological preferences of macroinvertebrates including body size, gill type, feeding habit, and velocity preferences were selected and resolved into 17 trait attributes. The sink hydraulic zones such as pools were indicated to favour exposure to and ingestion of microplastics compared to the flush zones such as riffles and fast runs. Large body size macroinvertebrates were associated with the sink zone. Taxa with a very small body size had a higher likelihood for microplastics ingestion than taxa with other body sizes. Collectorgathering macroinvertebrates taxa that have operculate gills with small body sizes were more prone to exposure to microplastics in hydraulic biotopes with slow to very slow velocities. Fibres were the most abundant plastic ingested by macroinvertebrates preferring the flush zone while fibres and fragments were mostly ingested by those preferring the sink zones. The binomial logistic model revealed a highly significant result for the likelihood of operculate gill shape to clog in the sink hydraulic zone. The result of the binomial logistic regression indicates the usefulness of the trait-based approach for predicting exposure to microplastics. Overall, the study reveals the influences of hydro-geomorphological features on the transport dynamics of microplastics and the usefulness of the trait-based approach in the ecological study of microplastics in riverine systems. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Owowenu, Enahoro Kennedy
- Date: 2024-10-11
- Subjects: Microplastics Environmental aspects , Water quality biological assessment , Hydrodynamics , Hydrogeomorphology , Biotope , Flow type
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466666 , vital:76765 , DOI https://doi.org/10.21504/10962/466666
- Description: Microplastics in rivers pose an ecological risk. Hydraulic biotopes form distinct flow patches that vary longitudinally along the river, potentially influencing the transport dynamics of microplastics. Macroinvertebrates exhibit adaptations to different hydraulic biotopes through their unique traits. These traits can mediate their exposure to microplastics, thereby imposing selective pressures on these organisms. Different taxa often demonstrate preferences for specific hydraulic biotopes characterized by distinct flow regimes. Understanding the transport dynamics of microplastics mediated by hydraulic biotopes and the potential exposure of macroinvertebrates at the hydraulic biotope scale is important for determining the fate of riverine microplastics and detecting species at risk. Both empirical and theoretical studies have highlighted the interconnectedness of hydrology, geomorphology, and microplastic transport in rivers, yet, there remains a gap in understanding how a hydro-geomorphological approach could enhance the understanding of the microplastic transport process. Little is known about the role of traits in driving macroinvertebrate exposure to microplastics at a scale relevant to ecological dynamics. This study addressed these gaps by applying a hydro-geomorphological approach to investigate the distribution of microplastics at the hydraulic biotope scale and assessed the potential exposure of macroinvertebrates using a trait-based approach. This study also explored the relationship between microplastic abundance and selected water physicochemical properties, as well as the influence of adjacent land use types. By integrating these aspects the research provided a comprehensive understanding of microplastics dynamics in river systems, shedding light on both environmental factors shaping their distribution and the potential impacts on aquatic organisms. The study was conducted over the wet and dry seasons (October 2021 – July 2022) at 10 sites located in the upper, middle, and lower reaches of the Swartkops and Buffalo River systems in the Eastern Cape Province of South Africa. The hydraulic biotopes (i.e., pools, runs, riffles) were grouped into two conceptualised forms, namely, sink and flush hydraulic zones and were characterized by hydraulic indices such as the Froude number and the Reynolds number. The flush hydraulic zone represents hydraulic biotopes where microplastics can potentially be remobilized quickly into suspension, and the sink represents biotopes where microplastics can potentially accumulate and remobilisation is far slower. Fast-to-moderate flowing hydraulic biotopes were conceptualised as microplastics flush zones while slow-flowing to still biotopes as microplastic sink zones. Samples were collected at different depths in each hydraulic zone to quantify suspended and settled forms of microplastics. Microplastics targeted in this study ranged in size from 0.063 mm to less than 5 mm. Classification was achieved through microscopic observation, and confirmation via Fourier Transform Infrared Spectroscopy (FTIR-ATR) was conducted for samples ranging from 0.5 mm to less than 5 mm. At the site level, settled microplastics showed statistically significant spatial and temporal variations between the sites, and between the seasons (P < 0.05). The suspended microplastic varied only spatially. Fibres and fragments were the dominant microplastic shape, while polyethylene and polypropylene were the dominant microplastic polymers. Suspended microplastics showed statistically significant variation between urban land cover and other land cover categories (industrial, agricultural, rural, and natural land cover). Microplastics abundance was associated with high levels of turbidity, total suspended solids, total inorganic nitrogen, higher temperatures and increasing electrical conductivity. At the hydraulic biotope scale, the mean occurrence of suspended microplastics (1.76 ± 1.44 items/L; mean + SD) in the flush hydraulic zone was higher than that in the sink zone (1.54 ± 1.46 items/L), while settled microplastics were more abundant in the sink hydraulic zone (1.82 ± 1.98 items/L) than the flush hydraulic zone (1.32 ± 1.49 items/L). This observation was in line with the prediction in this study. The mean suspended and settled microplastics concentrations were higher during the wet season across the flush and sink hydraulic zones than in the dry season. Global multivariate analysis of variance (MANOVA) and two-way analysis of variance (ANOVA) revealed significant spatial and temporal variations in settled microplastics abundances between the flush and sink hydraulic zones. The results indicated that geomorphologically defined units such as riffles and moderate to fast runs (flush) generally contained lower amounts of settled microplastics compared to pools and backwaters (sink). However, this distinction between the flush and sink microplastic zones was observed only for settled microplastics and not for suspended microplastics. Suspended and settled microplastics showed a statistically significant relationship with the Froude number index. The generalised additive model indicated that settled microplastics abundance distribution decreased significantly with increasing Froude number value in the flush zone. Suspended microplastics decreased at low Froude number values and showed an increasing trend at higher Froude number values of about 0.75. The results indicate the usefulness of the hydraulic biotope scale microplastic monitoring approach in detecting microplastic hotspots and explaining variations in microplastics abundances driven by instream hydraulics. Four traits and ecological preferences of macroinvertebrates including body size, gill type, feeding habit, and velocity preferences were selected and resolved into 17 trait attributes. The sink hydraulic zones such as pools were indicated to favour exposure to and ingestion of microplastics compared to the flush zones such as riffles and fast runs. Large body size macroinvertebrates were associated with the sink zone. Taxa with a very small body size had a higher likelihood for microplastics ingestion than taxa with other body sizes. Collectorgathering macroinvertebrates taxa that have operculate gills with small body sizes were more prone to exposure to microplastics in hydraulic biotopes with slow to very slow velocities. Fibres were the most abundant plastic ingested by macroinvertebrates preferring the flush zone while fibres and fragments were mostly ingested by those preferring the sink zones. The binomial logistic model revealed a highly significant result for the likelihood of operculate gill shape to clog in the sink hydraulic zone. The result of the binomial logistic regression indicates the usefulness of the trait-based approach for predicting exposure to microplastics. Overall, the study reveals the influences of hydro-geomorphological features on the transport dynamics of microplastics and the usefulness of the trait-based approach in the ecological study of microplastics in riverine systems. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2024
- Full Text:
- Date Issued: 2024-10-11
A social realist account of the way smallholder farmers exercised their agency in the adoption of climate-smart agriculture practices in degraded landscapes in Machubeni, Eastern Cape, South Africa
- Authors: Mbengo, Idah
- Date: 2024-10-11
- Subjects: Climate-smart agriculture , Climatic changes South Africa , Climate change adaptation South Africa Eastern Cape , Social realism , Farms, Small South Africa Eastern Cape
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466884 , vital:76795 , DOI https://doi.org/10.21504/10962/466884
- Description: Over the last two decades, climate-smart agriculture (CSA) has been promoted as a way to address the challenges of climate change for smallholder farmers' productivity, food security and livelihoods. Given concerns about climate change, many studies have contributed to developing an understanding of resilience building and crop and livestock systems adaptation. Despite evidence of the effectiveness of CSA practices, several studies report on their limited uptake by farmers involved in various projects. The reasons for low rates of adoption remain unclear. In this context, the study on which this thesis is based drew on Bhaskar’s critical realism and Archer’s social realism to explore the way smallholder farmers in five villages in a rural area in South Africa were enabled and constrained as they exercised their agency in a project intended to introduce them to CSA practices. The study was not about adaptation and resilience building per se but rather, following Bhaskar and Archer, sought to identify the generative mechanisms enabling and constraining the adoption of CSA practices. Bhaskar’s critical realism posits a view of reality as layered. The topmost layer of reality is the Empirical. This consists of observations and experiences of the world around us and is understood to be relative. The second layer, the Actual, is the layer of events from which observations and experiences located at the level of the Empirical emerge. Events at the level of the Actual and experiences and observations at the level of the Empirical emerge from an interplay of mechanisms at the deepest layer of reality identified by Bhaskar, as the Real. In positing a layered ontology, critical realism allows for the relativity of experiences and observations while, at the same time, acknowledging the reality of structures and mechanisms, which cannot be directly observed but nonetheless exist. Archer’s work on agency accords personal powers and properties (PEPs) to all individuals. Although all individuals have the power to act in relation to the world around them, they are nonetheless conditioned by their previous histories and experiences as they do so. As individuals set about exercising their agency, they are enabled or constrained by structures and mechanisms in two domains at the level of the Real which are understood to possess their own powers and properties: the structural domain and the cultural domain. In addition to drawing on Archer’s conceptualisation of the interaction between agency, structure and culture, the study also uses her “morphogenetic framework” which allows for the identification of ‘whose conceptual shifts are responsible for which structural changes, when, where and under what conditions’ (Archer, 1998: 361) and for understanding change as a series of never-ending cycles. The first phase of Archer’s morphogenetic framework, entitled T1, involves social and cultural conditioning. In the study, T1 was understood to be the time until 2017 when the project on which the study focused began. The second phase, T2 to T3, is the phase of social and cultural interaction as agents exercise their PEPs to pursue concerns they have identified for themselves and encounter structural emergent powers and properties (SEPs) and cultural emergent powers and properties (CEPs) of mechanisms located in the domains of structure and culture as they do so. The final phase of the framework, T4, allows for an evaluation of what has changed and what has not changed. My claim is that the uptake of CSA practices is impacted by different forms of consciousness or ways of experiencing the world, which is the result of the social and cultural conditioning of different groups involved in the project at T1, and clashes between them. The use of the framework drawing on critical realism and social realism allowed for the identification of these different forms of consciousness in different social groups (project facilitators, elderly farmers and the youth). These different forms of consciousness were understood to condition the agency of the three groups and thus enable or constrain the introduction of CSA practices and how they were taken up. Elderly women in the project had been conditioned to be caregivers and to see their roles tending kitchen gardens as part of their identity. This consciousness led to the uptake of CSA practices in their home gardens. By contrast, young people engaged with the project shared a very different way of experiencing the world. They were better educated and had been socialised into using social media and watching films on electronic devices from a young age. As a result, they valued the role of money in accessing consumer goods and the good life and thus valued paid employment rather than working on the land to provide subsistence. This led to a limited uptake of CSA practices. It is envisaged that insights from the study will offer new ways of understanding what might otherwise be seen as resistance to adopting CSA practices as well as new ways of engaging with different groups of agents involved in projects in the future. The study demonstrates the explanatory power of critical realism and social realism to analyse a climate change adaptation project. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Mbengo, Idah
- Date: 2024-10-11
- Subjects: Climate-smart agriculture , Climatic changes South Africa , Climate change adaptation South Africa Eastern Cape , Social realism , Farms, Small South Africa Eastern Cape
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466884 , vital:76795 , DOI https://doi.org/10.21504/10962/466884
- Description: Over the last two decades, climate-smart agriculture (CSA) has been promoted as a way to address the challenges of climate change for smallholder farmers' productivity, food security and livelihoods. Given concerns about climate change, many studies have contributed to developing an understanding of resilience building and crop and livestock systems adaptation. Despite evidence of the effectiveness of CSA practices, several studies report on their limited uptake by farmers involved in various projects. The reasons for low rates of adoption remain unclear. In this context, the study on which this thesis is based drew on Bhaskar’s critical realism and Archer’s social realism to explore the way smallholder farmers in five villages in a rural area in South Africa were enabled and constrained as they exercised their agency in a project intended to introduce them to CSA practices. The study was not about adaptation and resilience building per se but rather, following Bhaskar and Archer, sought to identify the generative mechanisms enabling and constraining the adoption of CSA practices. Bhaskar’s critical realism posits a view of reality as layered. The topmost layer of reality is the Empirical. This consists of observations and experiences of the world around us and is understood to be relative. The second layer, the Actual, is the layer of events from which observations and experiences located at the level of the Empirical emerge. Events at the level of the Actual and experiences and observations at the level of the Empirical emerge from an interplay of mechanisms at the deepest layer of reality identified by Bhaskar, as the Real. In positing a layered ontology, critical realism allows for the relativity of experiences and observations while, at the same time, acknowledging the reality of structures and mechanisms, which cannot be directly observed but nonetheless exist. Archer’s work on agency accords personal powers and properties (PEPs) to all individuals. Although all individuals have the power to act in relation to the world around them, they are nonetheless conditioned by their previous histories and experiences as they do so. As individuals set about exercising their agency, they are enabled or constrained by structures and mechanisms in two domains at the level of the Real which are understood to possess their own powers and properties: the structural domain and the cultural domain. In addition to drawing on Archer’s conceptualisation of the interaction between agency, structure and culture, the study also uses her “morphogenetic framework” which allows for the identification of ‘whose conceptual shifts are responsible for which structural changes, when, where and under what conditions’ (Archer, 1998: 361) and for understanding change as a series of never-ending cycles. The first phase of Archer’s morphogenetic framework, entitled T1, involves social and cultural conditioning. In the study, T1 was understood to be the time until 2017 when the project on which the study focused began. The second phase, T2 to T3, is the phase of social and cultural interaction as agents exercise their PEPs to pursue concerns they have identified for themselves and encounter structural emergent powers and properties (SEPs) and cultural emergent powers and properties (CEPs) of mechanisms located in the domains of structure and culture as they do so. The final phase of the framework, T4, allows for an evaluation of what has changed and what has not changed. My claim is that the uptake of CSA practices is impacted by different forms of consciousness or ways of experiencing the world, which is the result of the social and cultural conditioning of different groups involved in the project at T1, and clashes between them. The use of the framework drawing on critical realism and social realism allowed for the identification of these different forms of consciousness in different social groups (project facilitators, elderly farmers and the youth). These different forms of consciousness were understood to condition the agency of the three groups and thus enable or constrain the introduction of CSA practices and how they were taken up. Elderly women in the project had been conditioned to be caregivers and to see their roles tending kitchen gardens as part of their identity. This consciousness led to the uptake of CSA practices in their home gardens. By contrast, young people engaged with the project shared a very different way of experiencing the world. They were better educated and had been socialised into using social media and watching films on electronic devices from a young age. As a result, they valued the role of money in accessing consumer goods and the good life and thus valued paid employment rather than working on the land to provide subsistence. This led to a limited uptake of CSA practices. It is envisaged that insights from the study will offer new ways of understanding what might otherwise be seen as resistance to adopting CSA practices as well as new ways of engaging with different groups of agents involved in projects in the future. The study demonstrates the explanatory power of critical realism and social realism to analyse a climate change adaptation project. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2024
- Full Text:
- Date Issued: 2024-10-11
A social realist analysis of health policy development: interests, ideas and community pharmacists
- Authors: Allan, Lucie
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466328 , vital:76718
- Description: Access restricted. Expected release in 2026. , Thesis (PhD) -- Faculty of Pharmacy, Pharmacy, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Allan, Lucie
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466328 , vital:76718
- Description: Access restricted. Expected release in 2026. , Thesis (PhD) -- Faculty of Pharmacy, Pharmacy, 2024
- Full Text:
- Date Issued: 2024-10-11
A social realist analysis of the professional identity formation of lecturers emerging from completing professional development at a South African research-intensive university
- Authors: Adams, Anthea
- Date: 2024-10-11
- Subjects: Identity (Psychology) in education , Academic development , Staff development , Social realism , Critical realism , Scholarship of teaching and learning , Education, Higher South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466372 , vital:76722 , DOI https://doi.org/10.21504/10962/466372
- Description: This doctoral study is part of a Department of Higher Education and Training (DHET) capacity development project, Phakamisa. Using Margaret Archer's Social Realism as a substantive theory and methodological tool and Roy Bhaskar's Critical Realism as a meta-theory, I was able to identify and explain the interplay between the structural, cultural and agential mechanisms within a professional development course that enabled or constrained the emergence of lecturers' professional academic identities. My research participants are fourteen lecturers who completed the Postgraduate Diploma in Higher Education (PGDip HE) at Rhodes University between 2007 and 2017. Social Realism's explanatory methodologies, analytical dualism, and the morphogenetic cycle allowed me to provide causal explanations and account for the historicity of the emergence of lecturers' professional academic identities as teachers. A qualitative research design involving case study research allowed me to search for generative mechanisms to understand and explain the conditioning influence of often unobservable phenomena and underlying mechanisms in developing lecturers' identities as teachers in a research-intensive university. As strong social actors imbued with power and material resources, university leadership should consider the constraining influence of contextual conditions, such as the hegemony of disciplinary research versus research in the Scholarship of Teaching and Learning (SoTL). The socio-cultural (S-C) interactions of the fourteen lecturers (agents) signal the possibilities for structural, cultural and agential morphogenesis when agents choose to exercise their agency, i.e., their personal emergent properties (PEPs) to mediate prevalent structural and cultural emergent properties (SEPs and CEPs) enabling or constraining their personal projects. Lecturers' personal projects are the courses of action they intentionally engage in as they strive to establish sustainable yet evolving practices as teachers in their disciplines. This thesis shows that exercising their PEPs involves subjective reflexivity and transforming from primary agents to corporate agents due to collective action and alliances with like-minded peers and colleagues to shape the teaching and learning agenda in their respective departments and the broader higher education context. Triple morphogenesis of lecturers' agency occurred through their realisation as social actors. It signified the formation of their professional identities as teachers and how they uniquely embodied and enacted their teacher roles. , Hierdie doktorale studie is deel van 'n Departement van Hoër Onderwys en Opleiding (DHOO) kapasiteitsontwikkelingsprojek, naamlik Phakamisa. Deur gebruik te maak van Margaret Archer se Sosiale Realisme ("Social Realism") as 'n substantiewe teorie en metodologiese instrument, en Roy Bhaskar se Kritiese Realisme ("Critical Realism") as 'n metateorie, was ek in staat om die wisselwerking tussen die strukturele, kulturele en agentiese meganismes binne 'n professionele ontwikkelingskursus te identifiseer en te verduidelik wat die ontstaan van dosente se professionele akademiese identiteite moontlik gemaak of beperk het. Die deelnemers in my navorsing is veertien dosente wat die Nagraadse Diploma in Hoër Onderwys (NGDip HO) aan Rhodes Universiteit tussen 2007 en 2017 voltooi het. Sosiale Realisme se verklarende metodologieë, analitiese dualisme en die morfogenetiese siklus het my toegelaat om oorsaaklike verklarings te verskaf en die historisiteit van die ontstaan van dosente se professionele akademiese identiteite as onderwysers te verantwoord. ’n Kwalitatiewe navorsingsontwerp wat gevallestudienavorsing behels het, het my toegelaat om na generatiewe meganismes te soek om die kondisionerende invloed van dikwels onwaarneembare verskynsels en onderliggende meganismes in die ontwikkeling van dosente se identiteit as onderwysers in ’n navorsingsintensiewe universiteit te verstaan en te verduidelik. As sterk sosiale rolspelers deurdrenk met mag en materiële hulpbronne, behoort universiteitsleierskap die beperkende invloed van kontekstuele toestande, soos die hegemonie van dissiplinêre navorsing versus navorsing in die Akademieskap van Onderrig en Leer (AvOL, of in Engels "Scholarship of Teaching and Learning", afgekort na SoTL) in ag te neem. Die sosiokulturele (S-K) interaksie van die veertien dosente (agente) dui op die moontlikhede vir strukturele, kulturele en agentiale morfogenese wanneer agente doelbewus kies om hul agentskap uit te oefen, dit wil sê hul persoonlike ontluikende eienskappe (in Engels "personal emergent properties", afgekort na PEPs) om heersende strukturele en kulturele ontluikende eienskappe te bemiddel (in Engels "cultural emergent properties", afgekort na CEPs) wat hul persoonlike projekte moontlik maak of beperk. Dosente se persoonlike projekte is die aksies wat hulle doelbewus aangepak het terwyl hulle daarna gestreef het om volhoubare dog ontwikkelende praktyke as onderwysers in hul dissiplines te vestig. Hierdie tesis dui aan dat die uitoefening van hul persoonlike ontluikende eienskappe ("PEPs") behels subjektiewe refleksiwiteit en transformasie van primêre agente na korporatiewe agente as gevolg van kollektiewe optrede en alliansies met eendersdenkende eweknieë en kollegas om die onderrigen leeragenda in hul onderskeie departemente en die breër hoëronderwyskonteks te beïnvloed. Drievoudige morfogenese van dosente se agentskap het plaasgevind deur hul verwesenliking as sosiale rolspelers. Dit het die vorming van hul professionele identiteite as onderwysers aangedui en die unieke manier hoe hulle hul onderwyserrolle interpreteer en uitleef. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Adams, Anthea
- Date: 2024-10-11
- Subjects: Identity (Psychology) in education , Academic development , Staff development , Social realism , Critical realism , Scholarship of teaching and learning , Education, Higher South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466372 , vital:76722 , DOI https://doi.org/10.21504/10962/466372
- Description: This doctoral study is part of a Department of Higher Education and Training (DHET) capacity development project, Phakamisa. Using Margaret Archer's Social Realism as a substantive theory and methodological tool and Roy Bhaskar's Critical Realism as a meta-theory, I was able to identify and explain the interplay between the structural, cultural and agential mechanisms within a professional development course that enabled or constrained the emergence of lecturers' professional academic identities. My research participants are fourteen lecturers who completed the Postgraduate Diploma in Higher Education (PGDip HE) at Rhodes University between 2007 and 2017. Social Realism's explanatory methodologies, analytical dualism, and the morphogenetic cycle allowed me to provide causal explanations and account for the historicity of the emergence of lecturers' professional academic identities as teachers. A qualitative research design involving case study research allowed me to search for generative mechanisms to understand and explain the conditioning influence of often unobservable phenomena and underlying mechanisms in developing lecturers' identities as teachers in a research-intensive university. As strong social actors imbued with power and material resources, university leadership should consider the constraining influence of contextual conditions, such as the hegemony of disciplinary research versus research in the Scholarship of Teaching and Learning (SoTL). The socio-cultural (S-C) interactions of the fourteen lecturers (agents) signal the possibilities for structural, cultural and agential morphogenesis when agents choose to exercise their agency, i.e., their personal emergent properties (PEPs) to mediate prevalent structural and cultural emergent properties (SEPs and CEPs) enabling or constraining their personal projects. Lecturers' personal projects are the courses of action they intentionally engage in as they strive to establish sustainable yet evolving practices as teachers in their disciplines. This thesis shows that exercising their PEPs involves subjective reflexivity and transforming from primary agents to corporate agents due to collective action and alliances with like-minded peers and colleagues to shape the teaching and learning agenda in their respective departments and the broader higher education context. Triple morphogenesis of lecturers' agency occurred through their realisation as social actors. It signified the formation of their professional identities as teachers and how they uniquely embodied and enacted their teacher roles. , Hierdie doktorale studie is deel van 'n Departement van Hoër Onderwys en Opleiding (DHOO) kapasiteitsontwikkelingsprojek, naamlik Phakamisa. Deur gebruik te maak van Margaret Archer se Sosiale Realisme ("Social Realism") as 'n substantiewe teorie en metodologiese instrument, en Roy Bhaskar se Kritiese Realisme ("Critical Realism") as 'n metateorie, was ek in staat om die wisselwerking tussen die strukturele, kulturele en agentiese meganismes binne 'n professionele ontwikkelingskursus te identifiseer en te verduidelik wat die ontstaan van dosente se professionele akademiese identiteite moontlik gemaak of beperk het. Die deelnemers in my navorsing is veertien dosente wat die Nagraadse Diploma in Hoër Onderwys (NGDip HO) aan Rhodes Universiteit tussen 2007 en 2017 voltooi het. Sosiale Realisme se verklarende metodologieë, analitiese dualisme en die morfogenetiese siklus het my toegelaat om oorsaaklike verklarings te verskaf en die historisiteit van die ontstaan van dosente se professionele akademiese identiteite as onderwysers te verantwoord. ’n Kwalitatiewe navorsingsontwerp wat gevallestudienavorsing behels het, het my toegelaat om na generatiewe meganismes te soek om die kondisionerende invloed van dikwels onwaarneembare verskynsels en onderliggende meganismes in die ontwikkeling van dosente se identiteit as onderwysers in ’n navorsingsintensiewe universiteit te verstaan en te verduidelik. As sterk sosiale rolspelers deurdrenk met mag en materiële hulpbronne, behoort universiteitsleierskap die beperkende invloed van kontekstuele toestande, soos die hegemonie van dissiplinêre navorsing versus navorsing in die Akademieskap van Onderrig en Leer (AvOL, of in Engels "Scholarship of Teaching and Learning", afgekort na SoTL) in ag te neem. Die sosiokulturele (S-K) interaksie van die veertien dosente (agente) dui op die moontlikhede vir strukturele, kulturele en agentiale morfogenese wanneer agente doelbewus kies om hul agentskap uit te oefen, dit wil sê hul persoonlike ontluikende eienskappe (in Engels "personal emergent properties", afgekort na PEPs) om heersende strukturele en kulturele ontluikende eienskappe te bemiddel (in Engels "cultural emergent properties", afgekort na CEPs) wat hul persoonlike projekte moontlik maak of beperk. Dosente se persoonlike projekte is die aksies wat hulle doelbewus aangepak het terwyl hulle daarna gestreef het om volhoubare dog ontwikkelende praktyke as onderwysers in hul dissiplines te vestig. Hierdie tesis dui aan dat die uitoefening van hul persoonlike ontluikende eienskappe ("PEPs") behels subjektiewe refleksiwiteit en transformasie van primêre agente na korporatiewe agente as gevolg van kollektiewe optrede en alliansies met eendersdenkende eweknieë en kollegas om die onderrigen leeragenda in hul onderskeie departemente en die breër hoëronderwyskonteks te beïnvloed. Drievoudige morfogenese van dosente se agentskap het plaasgevind deur hul verwesenliking as sosiale rolspelers. Dit het die vorming van hul professionele identiteite as onderwysers aangedui en die unieke manier hoe hulle hul onderwyserrolle interpreteer en uitleef. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 2024
- Full Text:
- Date Issued: 2024-10-11
A systematic revision of Aprionyx Barnard, an endemic South African genus of Leptophlebiidae (Ephemeroptera)
- Authors: Ferreira, Ina Susan
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466770 , vital:76777 , DOI https://doi.org/10.21504/10962/466770
- Description: Aprionyx Barnard, 1940 is the most speciose genus of Leptophlebiidae in South Africa and endemic to the southern region. Like the other African Leptophlebiidae, Aprionyx has received limited research. The earliest described Aprionyx species were based only on adults that were then placed in Atalophlebia Eaton, 1881. The first descriptions of nymphs were contributed by Barnard (1932), with the smooth claws of the nymphs being the distinctive feature that allowed him to create Aprionyx for all of the South African species placed in Atalophlebia at that time. This research aimed to improve knowledge of Aprionyx species by revising its molecular and morphological systematics. Molecular phylogenetic analysis of the COI, 16S and 28S genes generated a species tree illustrating the species’ relationships within Aprionyx. Species delimitation analyses (bPTP and GMYC methods) were generally congruent with the molecular phylogenetic species composition. The phylogeny identified up to ten potentially new species, a substantial increase in the species diversity of Aprionyx. Review of the descriptions of the eight named Aprionyx species resulted in major nomenclatural changes concerning A. tabularis (Eaton, 1884), A. phoeocera (Lestage, 1924) stat. rev. and A. intermedius Barnard, 1932 n. syn. With the redescriptions of all currently known species, the nymph of A. rubicundus Barnard, 1932 was described for the first time. An identification key to the species of Aprionyx was compiled from newly recognized descriptive characteristics and, for the first time, includes both imagos and nymphs. Molecular and morphological phylogenetic analyses recovered Aprionyx as monophyletic, although this was poorly supported morphologically. The phylogenies were topologically congruent and identified two clear geographically separated clades, a western and eastern Aprionyx group. Molecularly, morphologically and geographically, these two clades were recovered as two clearly distinct groups within the genus. The analyses further identified three lineages in Aprionyx: rubicundus, pellucidulus and eastern Aprionyx. The estimated age of Aprionyx indicated that initial diversification occurred during the Cretaceous (approximately 100 ma). Aprionyx peterseni (Lestage, 1924) was shown as the oldest of the analysed species, and the main drivers to species diversification were possibly the glacial cycles of the Quaternary period, through the mechanism of river anastomosis during fluctuating sea levels. Further research is needed to strengthen the support for the hypothesis identified in this study, but a substantial foundation has been laid by this work for future research, conservation and environmental decision-making. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Ferreira, Ina Susan
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466770 , vital:76777 , DOI https://doi.org/10.21504/10962/466770
- Description: Aprionyx Barnard, 1940 is the most speciose genus of Leptophlebiidae in South Africa and endemic to the southern region. Like the other African Leptophlebiidae, Aprionyx has received limited research. The earliest described Aprionyx species were based only on adults that were then placed in Atalophlebia Eaton, 1881. The first descriptions of nymphs were contributed by Barnard (1932), with the smooth claws of the nymphs being the distinctive feature that allowed him to create Aprionyx for all of the South African species placed in Atalophlebia at that time. This research aimed to improve knowledge of Aprionyx species by revising its molecular and morphological systematics. Molecular phylogenetic analysis of the COI, 16S and 28S genes generated a species tree illustrating the species’ relationships within Aprionyx. Species delimitation analyses (bPTP and GMYC methods) were generally congruent with the molecular phylogenetic species composition. The phylogeny identified up to ten potentially new species, a substantial increase in the species diversity of Aprionyx. Review of the descriptions of the eight named Aprionyx species resulted in major nomenclatural changes concerning A. tabularis (Eaton, 1884), A. phoeocera (Lestage, 1924) stat. rev. and A. intermedius Barnard, 1932 n. syn. With the redescriptions of all currently known species, the nymph of A. rubicundus Barnard, 1932 was described for the first time. An identification key to the species of Aprionyx was compiled from newly recognized descriptive characteristics and, for the first time, includes both imagos and nymphs. Molecular and morphological phylogenetic analyses recovered Aprionyx as monophyletic, although this was poorly supported morphologically. The phylogenies were topologically congruent and identified two clear geographically separated clades, a western and eastern Aprionyx group. Molecularly, morphologically and geographically, these two clades were recovered as two clearly distinct groups within the genus. The analyses further identified three lineages in Aprionyx: rubicundus, pellucidulus and eastern Aprionyx. The estimated age of Aprionyx indicated that initial diversification occurred during the Cretaceous (approximately 100 ma). Aprionyx peterseni (Lestage, 1924) was shown as the oldest of the analysed species, and the main drivers to species diversification were possibly the glacial cycles of the Quaternary period, through the mechanism of river anastomosis during fluctuating sea levels. Further research is needed to strengthen the support for the hypothesis identified in this study, but a substantial foundation has been laid by this work for future research, conservation and environmental decision-making. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2024
- Full Text:
- Date Issued: 2024-10-11
Activist radio and the struggle to empower audiences: a case study of the Zimbabwean history
- Authors: Chaunza, Garikai
- Date: 2024-10-11
- Subjects: Activism Zimbabwe , Radio broadcasting Political aspects Zimbabwe , Authoritarianism Zimbabwe , Democracy Zimbabwe , Zimbabwe Social conditions , Zimbabwe Politics and government
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466907 , vital:76797 , DOI https://doi.org/10.21504/10962/466907
- Description: This study is grounded in my 18-year career in journalism in Zimbabwe. This journey began in January 2006 at the Zimbabwe Broadcasting Corporation (ZBC), where I started as a news reporter. In June 2008, I left ZBC and transitioned to freelance roles, including work at Radio Voice of the People (VOP), which broadcasted from South Africa using Radio Netherlands' transmitters in Madagascar. Simultaneously, I corresponded for The Zimbabwean Newspaper, edited in the UK, printed in Johannesburg, South Africa, and distributed to Zimbabwe, Radio Netherlands, Free Speech Radio News (USA), KPFA Pacifica Foundation Radio (USA), and DW (German). More recently, my work has expanded into the digital domain, contributing to New Zimbabwe, an online newspaper for the Zimbabwean diaspora in the UK, before transitioning to Community Radio Harare. Throughout my 18-year career as a media practitioner and journalist in Zimbabwe, I faced constant state-sanctioned interference, and even physical violence, while executing my responsibilities. Initially, at the Zimbabwe Broadcasting Corporation (ZBC), several colleagues and I, including our news editor, were politically victimised and ultimately fired for covering opposition political players and human rights activists. Later, when I was operating outside state-established media outlets, I experienced a series of threats, intimidation, arrests and detentions by state security. This was also true during my six-year tenure as the chairperson of the Media Institute of Southern Africa's Harare advocacy committee. This experience underscored the importance of studying the history of media activism in this country, focusing on the role that activists have played sustaining the alternative media despite intimidation by the state. I am convinced of the importance documenting their experiences, capturing their contribution to the creation of alternative communication platforms for marginalised audiences. In exploring the literature I discovered that the traditions of activist media, in which I have been involved myself, are rooted in a much older history that can be traced back to pre-independent Zimbabwe. At that time, colonial authorities also restricted media freedoms and employed violence against pro-democracy activities, referred to as nationalists. I decided, for the purpose of this study, to delve into this pre-history of media activism in Zimbabwe, focusing on radio in particular. I wished to gain insight into the way media activists have, over time, sustained their involvement in the traditions of radio practice that can empower marginalised communities. I was conscious that the continued survival of activist radio in this country has often been arduous, with activists facing harassment, arrests, and detentions by authoritarian administrations resisting the opening up of democratic spaces. I wished to trace this history of resistance from its origins in the mid-twentieth century to the time of my own involvement in such radio in the 21st century. In particular, I hoped to identify shared normative foundations as well as shared practices for the implementation of these ideals. Chapter One of the study explores the history of activist radio from the mid-20th century to the present, identifying five distinct phases in Zimbabwe's socio-political history and illustrating how each phase shaped the media landscape. Building on this, Chapter Two establishes a theoretical framework underpinning the values and principles driving media activists to create people-oriented radio projects to empower marginalized communities. Chapter Three delves into the documented history of activist radio within the broader context of media activism in Zimbabwe, engaging with each of the five key moments detailed in Chapter One. Chapter Four outlines the research plan for the empirical fieldwork and discusses its implementation. In Chapter Five, I present interviews with radio activists from the 1970s' nationalist radio and those involved in the pirate radio tradition that re-emerged at the turn of the millennium, sharing their practical experiences. Chapter Six focuses on interviews with community radio advocates, detailing their involvement in radio activism during the first decade of the millennium. Finally, Chapter Seven examines the activities of community radio practitioners, exploring their experiences with unlicensed radio projects and highlighting their creative endeavours. , Thesis (PhD) -- Faculty of Humanities, Journalism and Media Studies, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Chaunza, Garikai
- Date: 2024-10-11
- Subjects: Activism Zimbabwe , Radio broadcasting Political aspects Zimbabwe , Authoritarianism Zimbabwe , Democracy Zimbabwe , Zimbabwe Social conditions , Zimbabwe Politics and government
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466907 , vital:76797 , DOI https://doi.org/10.21504/10962/466907
- Description: This study is grounded in my 18-year career in journalism in Zimbabwe. This journey began in January 2006 at the Zimbabwe Broadcasting Corporation (ZBC), where I started as a news reporter. In June 2008, I left ZBC and transitioned to freelance roles, including work at Radio Voice of the People (VOP), which broadcasted from South Africa using Radio Netherlands' transmitters in Madagascar. Simultaneously, I corresponded for The Zimbabwean Newspaper, edited in the UK, printed in Johannesburg, South Africa, and distributed to Zimbabwe, Radio Netherlands, Free Speech Radio News (USA), KPFA Pacifica Foundation Radio (USA), and DW (German). More recently, my work has expanded into the digital domain, contributing to New Zimbabwe, an online newspaper for the Zimbabwean diaspora in the UK, before transitioning to Community Radio Harare. Throughout my 18-year career as a media practitioner and journalist in Zimbabwe, I faced constant state-sanctioned interference, and even physical violence, while executing my responsibilities. Initially, at the Zimbabwe Broadcasting Corporation (ZBC), several colleagues and I, including our news editor, were politically victimised and ultimately fired for covering opposition political players and human rights activists. Later, when I was operating outside state-established media outlets, I experienced a series of threats, intimidation, arrests and detentions by state security. This was also true during my six-year tenure as the chairperson of the Media Institute of Southern Africa's Harare advocacy committee. This experience underscored the importance of studying the history of media activism in this country, focusing on the role that activists have played sustaining the alternative media despite intimidation by the state. I am convinced of the importance documenting their experiences, capturing their contribution to the creation of alternative communication platforms for marginalised audiences. In exploring the literature I discovered that the traditions of activist media, in which I have been involved myself, are rooted in a much older history that can be traced back to pre-independent Zimbabwe. At that time, colonial authorities also restricted media freedoms and employed violence against pro-democracy activities, referred to as nationalists. I decided, for the purpose of this study, to delve into this pre-history of media activism in Zimbabwe, focusing on radio in particular. I wished to gain insight into the way media activists have, over time, sustained their involvement in the traditions of radio practice that can empower marginalised communities. I was conscious that the continued survival of activist radio in this country has often been arduous, with activists facing harassment, arrests, and detentions by authoritarian administrations resisting the opening up of democratic spaces. I wished to trace this history of resistance from its origins in the mid-twentieth century to the time of my own involvement in such radio in the 21st century. In particular, I hoped to identify shared normative foundations as well as shared practices for the implementation of these ideals. Chapter One of the study explores the history of activist radio from the mid-20th century to the present, identifying five distinct phases in Zimbabwe's socio-political history and illustrating how each phase shaped the media landscape. Building on this, Chapter Two establishes a theoretical framework underpinning the values and principles driving media activists to create people-oriented radio projects to empower marginalized communities. Chapter Three delves into the documented history of activist radio within the broader context of media activism in Zimbabwe, engaging with each of the five key moments detailed in Chapter One. Chapter Four outlines the research plan for the empirical fieldwork and discusses its implementation. In Chapter Five, I present interviews with radio activists from the 1970s' nationalist radio and those involved in the pirate radio tradition that re-emerged at the turn of the millennium, sharing their practical experiences. Chapter Six focuses on interviews with community radio advocates, detailing their involvement in radio activism during the first decade of the millennium. Finally, Chapter Seven examines the activities of community radio practitioners, exploring their experiences with unlicensed radio projects and highlighting their creative endeavours. , Thesis (PhD) -- Faculty of Humanities, Journalism and Media Studies, 2024
- Full Text:
- Date Issued: 2024-10-11
Analyzing Microsporidia sp. MB from sequence to biology: comprehensive exploration of the genome, protein structures, and functions through extensive bioinformatics analysis
- Authors: Ang'ang'o, Lilian Mbaisi
- Date: 2024-10-11
- Subjects: Microsporidia , Whole genome sequencing , Proteins Structure , Symbiont , Malaria Prevention , Vector control
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466480 , vital:76734 , DOI https://doi.org/10.21504/10962/466480
- Description: Microsporidia are spore-forming intracellular organisms classified as the earliest divergent group within the Fungi kingdom. Microsporidia have been found widely affecting different hosts, including both vertebrates and invertebrates. The pathogenicity of microsporidia depends on their species and the host species they infect. Due to their obligate intracellular nature, microsporidia have extensively evolved. This is illustrated by their highly variable genome sizes and gene content. Being minimalist eukaryotes, the microsporidia genome is often associated with extreme gene reduction and compaction. However, these interesting microorganisms retain particular genes that help them acquire specific host nutrients, thereby relying heavily on their host for survival and proliferation. The mode of sexual reproduction of microsporidia has not been well-studied. Harnessing microsporidia in the laboratory is often a challenge, however, the advances in computational tools have made it cheaper and quicker to accurately predict and annotate these organisms to understand their mechanism of infection. Understanding the protein structure and function of these unique organisms is the baseline for providing insights into their biology and survival in their respective hosts. Microsporidia genomes contain a large proportion of hypothetical proteins of which their functions are not described. Vittaforma corneae ATCC 50505 was used as a model to highlight the functions and structure of these otherwise unknown proteins. A systematic annotation pipeline employing exhaustive computational tools was devised to carefully annotate the hypothetical proteins of V. corneae, aiming to characterize their structure and function.The genome of the novel microsporidian, Microsporidia sp. MB, a Plasmodium-transmission-blocking symbiont isolated from Anopheles mosquitoes in Sub-Saharan Africa, was sequenced, assembled, and annotated. The genome was found to contain over 2000 putative genes spanning its 5.9 Mb size and contained minimal repeats. Comparative phylogenomic analysis of Microsporidia sp. MB grouped this symbiont within the Enterocytozoonida (clade IV) microsporidia, clustering with its closest relative – V. corneae. Using robust computational techniques, prediction and characterization of the putative proteins of Microsporidia sp. MB was conducted. The decay of several proteins in the glycolytic pathway is one unique characteristic associated with microsporidia. The proteins retained or lost often vary across the microsporidian taxon. This study highlights the retention of most of the proteins involved in the glycolytic pathway in Microsporidia sp. MB. The available genome dataset of Microsporidia sp. MB was further used to infer its mode of sexual reproduction. The symbiont appears to have several meiotic-related gene orthologs, suggesting that it is capable of sexual reproduction. These findings describe the basic biology of Microsporidia sp. MB and provide a basis for future Next-Generation Sequencing, RNA sequencing experiments ultimately informing the application of this microorganism as a biological malaria control tool. , Thesis (PhD) -- Faculty of Science, Biochemistry, Microbiology and Bioinformatics, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Ang'ang'o, Lilian Mbaisi
- Date: 2024-10-11
- Subjects: Microsporidia , Whole genome sequencing , Proteins Structure , Symbiont , Malaria Prevention , Vector control
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466480 , vital:76734 , DOI https://doi.org/10.21504/10962/466480
- Description: Microsporidia are spore-forming intracellular organisms classified as the earliest divergent group within the Fungi kingdom. Microsporidia have been found widely affecting different hosts, including both vertebrates and invertebrates. The pathogenicity of microsporidia depends on their species and the host species they infect. Due to their obligate intracellular nature, microsporidia have extensively evolved. This is illustrated by their highly variable genome sizes and gene content. Being minimalist eukaryotes, the microsporidia genome is often associated with extreme gene reduction and compaction. However, these interesting microorganisms retain particular genes that help them acquire specific host nutrients, thereby relying heavily on their host for survival and proliferation. The mode of sexual reproduction of microsporidia has not been well-studied. Harnessing microsporidia in the laboratory is often a challenge, however, the advances in computational tools have made it cheaper and quicker to accurately predict and annotate these organisms to understand their mechanism of infection. Understanding the protein structure and function of these unique organisms is the baseline for providing insights into their biology and survival in their respective hosts. Microsporidia genomes contain a large proportion of hypothetical proteins of which their functions are not described. Vittaforma corneae ATCC 50505 was used as a model to highlight the functions and structure of these otherwise unknown proteins. A systematic annotation pipeline employing exhaustive computational tools was devised to carefully annotate the hypothetical proteins of V. corneae, aiming to characterize their structure and function.The genome of the novel microsporidian, Microsporidia sp. MB, a Plasmodium-transmission-blocking symbiont isolated from Anopheles mosquitoes in Sub-Saharan Africa, was sequenced, assembled, and annotated. The genome was found to contain over 2000 putative genes spanning its 5.9 Mb size and contained minimal repeats. Comparative phylogenomic analysis of Microsporidia sp. MB grouped this symbiont within the Enterocytozoonida (clade IV) microsporidia, clustering with its closest relative – V. corneae. Using robust computational techniques, prediction and characterization of the putative proteins of Microsporidia sp. MB was conducted. The decay of several proteins in the glycolytic pathway is one unique characteristic associated with microsporidia. The proteins retained or lost often vary across the microsporidian taxon. This study highlights the retention of most of the proteins involved in the glycolytic pathway in Microsporidia sp. MB. The available genome dataset of Microsporidia sp. MB was further used to infer its mode of sexual reproduction. The symbiont appears to have several meiotic-related gene orthologs, suggesting that it is capable of sexual reproduction. These findings describe the basic biology of Microsporidia sp. MB and provide a basis for future Next-Generation Sequencing, RNA sequencing experiments ultimately informing the application of this microorganism as a biological malaria control tool. , Thesis (PhD) -- Faculty of Science, Biochemistry, Microbiology and Bioinformatics, 2024
- Full Text:
- Date Issued: 2024-10-11
Assessing the impacts of Lantana camara and opportunities for ecological restoration after its removal: does clearing facilitate both soil and native vegetation recovery?
- Authors: Bolosha, Uviwe
- Date: 2024-10-11
- Subjects: Lantana camara , Restoration and conservation , Restoration ecology , Invasive plants , Physicochemical process , Soil seed banks , Invasion driver
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466524 , vital:76738 , DOI https://doi.org/10.21504/10962/466524
- Description: Invasive alien plants (IAPs) are one of the major contributing factors to biodiversity loss, and Lantana camara is among the top ten alien invaders worldwide. Lantana camara threatens native biodiversity and human health, prevents natural succession, and has an economic and environmental impact globally. With current climate change and future predictions, these IAPs are anticipated to continue posing huge threats to ecosystem composition, structure, and function. Even though L. camara is a widespread IAP, there is still limited knowledge in South Africa on how it influences soil physicochemical properties at the species level, vegetation communities, and soil seed banks at the community level following its invasion. There is also minimal knowledge on the management and control (i.e., clearing for restoration purposes) of L. camara in South Africa, especially in the Eastern Cape province of South Africa. To address the knowledge gap, this thesis was structured into three main aspects: understanding L. camara invasion mechanisms, evaluating invasion impacts on both the aboveground and belowground communities, and invasion management. The main objectives of this thesis were (i) to examine how L. camara invasion (at a species level) affected soil physicochemical properties across different seasons, (ii) to assess how L. camara influences natural vegetation (at a community level), (iii) to examine the effects of L. camara invasion (at the community level) on belowground soil seed banks and also assess the availability of pioneer native species and IAPs in the soil seed banks, and (iv) to evaluate soil and vegetation responses following L. camara clearing in comparison to invaded and uninvaded conditions. To answer these objectives, different studies were carried out in the Eastern Cape province, South Africa, on various farms within the Albany Thicket Biome. The results (Chapter 3) show that L. camara alters and modifies some soil physical properties, such as soil infiltration rate, repellency, and soil penetration resistance, in the communities it invades. A significant decrease in soil penetration under the L. camara canopy was observed compared to soils from the edge and out position. Moreover, significantly faster infiltration rates were observed in the canopy and edge positions than in the out position. The study also observed that these modifications in soil physical properties vary depending on the season. A seasonal comparison in soil penetration showed that soil was more compact in the dry season than the wet season, and significantly faster infiltration rates were observed in summer than in the other seasons. The soil collected under the invaded sampling positions was mostly wettable (80–100%), and not strongly, severely, or extremely repellent across all the seasons. The changes in soil properties caused by L. camara could create favourable conditions for its growth and invasion. Seasonal changes in soil properties also highlight how environmental conditions, especially temperature and rainfall patterns, can affect soil physical properties. The findings in Chapter 4 observed both the negative and positive impacts of L. camara, where the species did not have negative effects on species richness, diversity, or cover of some native species growth forms (i.e., graminoids and forbs). For all species, both species richness and Shannon-Wiener (H’) were significantly higher in the L. camara invaded condition compared to the uninvaded condition. The Simpson’s (J’) and Pielou’s evenness (D’) indices, however, showed no differences between the invasion conditions. Furthermore, the effects of L. camara on vegetation cover were growth form-dependent, with differences being noted for trees and shrubs but not for graminoids and forbs. Changes in vegetation structure and composition were also noted where L. camara created favourable conditions for some species to co-occur with it, meaning that its known trait of changing soil physicochemical properties could benefit some species. Generally, the results of this study showed that the effects of L. camara on vegetation are varied and do not have a predictable pattern, so they should not be generalised. The findings (Chapter 5) also indicate that the L. camara invasion had a negative impact on seedling abundance and composition but not species diversity and richness. This is evident through the decrease in seedling abundance of forbs and graminoids in the L. camara invaded condition. Lantana camara also acted as a refuge for some plant species, mostly native forbs and grasses, including Aptenia cordifolia, Chamaesyce prostrata, Oxalis spp., and Setaria spp., as well as alien forbs such as Bidens pilosa, Plantago lanceolata, and Taraxacum officinale, suggesting L. camara does not entirely eliminate less competitive plant species but can co-exist with them. Lantana camara also displaced some native species, and this could be associated with their displacement in the standing vegetation. Moreover, the species also displaced the seed banks of some alien species, thus showing its competitive ability. Overall, L. camara invasion negatively influenced soil seed bank seedling abundance and composition of some species, but not diversity and richness. The results in Chapter 6 indicated that clearing L. camara is an effective method for reducing its population. However, our findings suggest that clearing alone may not be enough to re-establish these communities with native species. This is because the results of this study showed varied changes in soil properties and native vegetation (species richness, species diversity, percentage cover, and composition) after L. camara clearing. For example, soil moisture and soil penetration resistance showed no significant differences among the invasion conditions; only monthly variations were observed. This is an indication that seasonality influenced these properties. Significantly lower soil infiltration rates were observed in the cleared condition compared to the other conditions and were influenced by the months and the interaction of the clearing conditions and months. The water droplet penetration time showed no significant difference among the clearing conditions over the three months, and all the soil collected from the three clearing conditions was mostly wettable. Soil chemical properties showed that the L. camara invaded and cleared conditions had significantly lower soil pH compared to the uninvaded condition, and an increase in soil pH was observed after clearing L. camara. Vegetation characteristics showed that both the Shannon-Wiener index (H') and the Simpson’s index (D') were lower in the invaded and cleared conditions compared to the uninvaded condition, and significant differences were observed. A slight increase in the H' and D' indices was also observed after clearing L. camara. The mean percentage cover for trees and shrubs was significantly higher in the invaded condition than in the cleared and uninvaded conditions. However, the mean percentage cover of forbs and graminoids was similar among the invaded, cleared, and uninvaded conditions, and no significant differences were observed. When L. camara was cleared, native species recovery was observed and was more notable in the understory species. Overall, some signs of vegetation recovery were observed, although challenges such as secondary invaders and re-invasion by L. camara were noted in the cleared areas. This chapter then concluded that active restoration interventions should be incorporated during restoration to fast-track soil and vegetation recovery. The findings of this thesis will make several significant contributions to the field of biological invasions and provide baseline information that can be used in future studies. These are discussed in the various research chapters. Overall, the thesis concludes that L. camara invasion has varied impacts on native vegetation and soil, and its clearance, should be prioritised to reduce the negative impacts. However, L. camara cleared areas (by WfW in South Africa) require follow-up and monitoring at an early stage to assess vegetation and soil restoration success. In addition, active management measures after L. camara’s removal should be considered for clearing programmes to yield positive ecosystem recovery. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Bolosha, Uviwe
- Date: 2024-10-11
- Subjects: Lantana camara , Restoration and conservation , Restoration ecology , Invasive plants , Physicochemical process , Soil seed banks , Invasion driver
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466524 , vital:76738 , DOI https://doi.org/10.21504/10962/466524
- Description: Invasive alien plants (IAPs) are one of the major contributing factors to biodiversity loss, and Lantana camara is among the top ten alien invaders worldwide. Lantana camara threatens native biodiversity and human health, prevents natural succession, and has an economic and environmental impact globally. With current climate change and future predictions, these IAPs are anticipated to continue posing huge threats to ecosystem composition, structure, and function. Even though L. camara is a widespread IAP, there is still limited knowledge in South Africa on how it influences soil physicochemical properties at the species level, vegetation communities, and soil seed banks at the community level following its invasion. There is also minimal knowledge on the management and control (i.e., clearing for restoration purposes) of L. camara in South Africa, especially in the Eastern Cape province of South Africa. To address the knowledge gap, this thesis was structured into three main aspects: understanding L. camara invasion mechanisms, evaluating invasion impacts on both the aboveground and belowground communities, and invasion management. The main objectives of this thesis were (i) to examine how L. camara invasion (at a species level) affected soil physicochemical properties across different seasons, (ii) to assess how L. camara influences natural vegetation (at a community level), (iii) to examine the effects of L. camara invasion (at the community level) on belowground soil seed banks and also assess the availability of pioneer native species and IAPs in the soil seed banks, and (iv) to evaluate soil and vegetation responses following L. camara clearing in comparison to invaded and uninvaded conditions. To answer these objectives, different studies were carried out in the Eastern Cape province, South Africa, on various farms within the Albany Thicket Biome. The results (Chapter 3) show that L. camara alters and modifies some soil physical properties, such as soil infiltration rate, repellency, and soil penetration resistance, in the communities it invades. A significant decrease in soil penetration under the L. camara canopy was observed compared to soils from the edge and out position. Moreover, significantly faster infiltration rates were observed in the canopy and edge positions than in the out position. The study also observed that these modifications in soil physical properties vary depending on the season. A seasonal comparison in soil penetration showed that soil was more compact in the dry season than the wet season, and significantly faster infiltration rates were observed in summer than in the other seasons. The soil collected under the invaded sampling positions was mostly wettable (80–100%), and not strongly, severely, or extremely repellent across all the seasons. The changes in soil properties caused by L. camara could create favourable conditions for its growth and invasion. Seasonal changes in soil properties also highlight how environmental conditions, especially temperature and rainfall patterns, can affect soil physical properties. The findings in Chapter 4 observed both the negative and positive impacts of L. camara, where the species did not have negative effects on species richness, diversity, or cover of some native species growth forms (i.e., graminoids and forbs). For all species, both species richness and Shannon-Wiener (H’) were significantly higher in the L. camara invaded condition compared to the uninvaded condition. The Simpson’s (J’) and Pielou’s evenness (D’) indices, however, showed no differences between the invasion conditions. Furthermore, the effects of L. camara on vegetation cover were growth form-dependent, with differences being noted for trees and shrubs but not for graminoids and forbs. Changes in vegetation structure and composition were also noted where L. camara created favourable conditions for some species to co-occur with it, meaning that its known trait of changing soil physicochemical properties could benefit some species. Generally, the results of this study showed that the effects of L. camara on vegetation are varied and do not have a predictable pattern, so they should not be generalised. The findings (Chapter 5) also indicate that the L. camara invasion had a negative impact on seedling abundance and composition but not species diversity and richness. This is evident through the decrease in seedling abundance of forbs and graminoids in the L. camara invaded condition. Lantana camara also acted as a refuge for some plant species, mostly native forbs and grasses, including Aptenia cordifolia, Chamaesyce prostrata, Oxalis spp., and Setaria spp., as well as alien forbs such as Bidens pilosa, Plantago lanceolata, and Taraxacum officinale, suggesting L. camara does not entirely eliminate less competitive plant species but can co-exist with them. Lantana camara also displaced some native species, and this could be associated with their displacement in the standing vegetation. Moreover, the species also displaced the seed banks of some alien species, thus showing its competitive ability. Overall, L. camara invasion negatively influenced soil seed bank seedling abundance and composition of some species, but not diversity and richness. The results in Chapter 6 indicated that clearing L. camara is an effective method for reducing its population. However, our findings suggest that clearing alone may not be enough to re-establish these communities with native species. This is because the results of this study showed varied changes in soil properties and native vegetation (species richness, species diversity, percentage cover, and composition) after L. camara clearing. For example, soil moisture and soil penetration resistance showed no significant differences among the invasion conditions; only monthly variations were observed. This is an indication that seasonality influenced these properties. Significantly lower soil infiltration rates were observed in the cleared condition compared to the other conditions and were influenced by the months and the interaction of the clearing conditions and months. The water droplet penetration time showed no significant difference among the clearing conditions over the three months, and all the soil collected from the three clearing conditions was mostly wettable. Soil chemical properties showed that the L. camara invaded and cleared conditions had significantly lower soil pH compared to the uninvaded condition, and an increase in soil pH was observed after clearing L. camara. Vegetation characteristics showed that both the Shannon-Wiener index (H') and the Simpson’s index (D') were lower in the invaded and cleared conditions compared to the uninvaded condition, and significant differences were observed. A slight increase in the H' and D' indices was also observed after clearing L. camara. The mean percentage cover for trees and shrubs was significantly higher in the invaded condition than in the cleared and uninvaded conditions. However, the mean percentage cover of forbs and graminoids was similar among the invaded, cleared, and uninvaded conditions, and no significant differences were observed. When L. camara was cleared, native species recovery was observed and was more notable in the understory species. Overall, some signs of vegetation recovery were observed, although challenges such as secondary invaders and re-invasion by L. camara were noted in the cleared areas. This chapter then concluded that active restoration interventions should be incorporated during restoration to fast-track soil and vegetation recovery. The findings of this thesis will make several significant contributions to the field of biological invasions and provide baseline information that can be used in future studies. These are discussed in the various research chapters. Overall, the thesis concludes that L. camara invasion has varied impacts on native vegetation and soil, and its clearance, should be prioritised to reduce the negative impacts. However, L. camara cleared areas (by WfW in South Africa) require follow-up and monitoring at an early stage to assess vegetation and soil restoration success. In addition, active management measures after L. camara’s removal should be considered for clearing programmes to yield positive ecosystem recovery. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2024
- Full Text:
- Date Issued: 2024-10-11
Assessing the status of the Barotse floodplain fishery and the implications of Australian redclaw crayfish Cherax quadricarinatus invasion on the fishery
- Authors: Nawa, Nawa
- Date: 2024-10-11
- Subjects: Zambezi Floodplains , Fishery resources Zambia Barotse Flood Plain , Introduced fishes Economic aspects , Cherax quadricarinatus , Fishery management
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466803 , vital:76780 , DOI https://doi.org/10.21504/10962/466803
- Description: Inland capture fisheries play an important role of supporting livelihoods of people in developing countries. Despite their significance these fisheries are often poorly monitored resulting in them being undervalued and often missing from policy and decision-making relating to food security and water use, particularly in third world countries. The Anthropocene has given rise to increased pressure on these systems, further justifying the need for monitoring activities to determine the ecosystem service provision status and the levels of existing and emerging threats to such services. This thesis focuses on the Barotse floodplain fishery of the Upper Zambezi system and the potential implications of the recent Cherax quadricarinatus invasion on the floodplain fishery. The thesis specifically assesses the current status of the fishery (Chapter 3), invasion dynamics of C. quadricarinatus (Chapter 4), economic impact of C. quadricarinatus on the fishery (Chapter 5) and fishers’ knowledge, awareness and perception of C. quadricarinatus (Chapter 6). To evaluate the current status of the fishery (Chapter 3), fisheries dependant surveys were conducted. The study revealed a multi-gear multi-species fishery with average catch rates of 5.83 kg per fisher per day and estimated annual harvest of 3123 tonnes per annum. The decline in catch rate, low mean sizes of species harvested, change in species composition, and predominant use of illegal fishing gear compared to previous surveys, suggested further overexploitation of fishery resources. The invasive C. quadricarinatus was identified as the most dominant by-catch species and more prevalent among fishers at the invasion core and in dry season. Analysis of the invasion dynamics of C. quadricarinatus (Chapter 4) involved extensive survey of the Barotse floodplain using collapsible promar traps. The study revealed significant up and down-stream spread from the 2019 range on the floodplain. Relative abundance was higher at the invasion core compared to the invasion edge while male to female sex ratio was not different between these zones, implying both sexes were acting as dispersers. Signals of environmental filtering were not detected while density dependent spatial sorting, and hydrological variation had a strong influence on C. quadricarinatus spread. To quantify economic impact C. quadricarinatus (Chapter 5) creel surveys were conducted during wet and dry season across the invasion range. The study showed that fish damage due to crayfish was limited to gillnets at the invasion core during the dry season and equated to the monetary loss of ~ US$ 21,000 per annum. In addition, gear damage and loss of time due to crayfish was experienced for various fishing gears but most prevalent at the invasion core and more so in dry season. Assessment of fishers’ awareness, knowledge and perception (Chapter 6) involved the use of social surveys administered at the invasion core. This component revealed that most of the respondents were aware of, but not knowledgeable about C. quadricarinatus. Respondents were not aware of any management information relating to C. quadricarinatus and consequently did not follow any management practices. The respondents were supportive of management interventions due to their perceived threat of C. quadricarinatus to the fishery. Age, education, and residence of respondents significantly influenced knowledge and perceptions of C. quadricarinatus. Findings from this study have important implications for the conservation of floodplain wetlands as it informs policy makers to put in place measures that address both overexploitation and aquatic invasive species dynamics to better facilitate sustainability of fisheries and conservation of biodiversity. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Nawa, Nawa
- Date: 2024-10-11
- Subjects: Zambezi Floodplains , Fishery resources Zambia Barotse Flood Plain , Introduced fishes Economic aspects , Cherax quadricarinatus , Fishery management
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466803 , vital:76780 , DOI https://doi.org/10.21504/10962/466803
- Description: Inland capture fisheries play an important role of supporting livelihoods of people in developing countries. Despite their significance these fisheries are often poorly monitored resulting in them being undervalued and often missing from policy and decision-making relating to food security and water use, particularly in third world countries. The Anthropocene has given rise to increased pressure on these systems, further justifying the need for monitoring activities to determine the ecosystem service provision status and the levels of existing and emerging threats to such services. This thesis focuses on the Barotse floodplain fishery of the Upper Zambezi system and the potential implications of the recent Cherax quadricarinatus invasion on the floodplain fishery. The thesis specifically assesses the current status of the fishery (Chapter 3), invasion dynamics of C. quadricarinatus (Chapter 4), economic impact of C. quadricarinatus on the fishery (Chapter 5) and fishers’ knowledge, awareness and perception of C. quadricarinatus (Chapter 6). To evaluate the current status of the fishery (Chapter 3), fisheries dependant surveys were conducted. The study revealed a multi-gear multi-species fishery with average catch rates of 5.83 kg per fisher per day and estimated annual harvest of 3123 tonnes per annum. The decline in catch rate, low mean sizes of species harvested, change in species composition, and predominant use of illegal fishing gear compared to previous surveys, suggested further overexploitation of fishery resources. The invasive C. quadricarinatus was identified as the most dominant by-catch species and more prevalent among fishers at the invasion core and in dry season. Analysis of the invasion dynamics of C. quadricarinatus (Chapter 4) involved extensive survey of the Barotse floodplain using collapsible promar traps. The study revealed significant up and down-stream spread from the 2019 range on the floodplain. Relative abundance was higher at the invasion core compared to the invasion edge while male to female sex ratio was not different between these zones, implying both sexes were acting as dispersers. Signals of environmental filtering were not detected while density dependent spatial sorting, and hydrological variation had a strong influence on C. quadricarinatus spread. To quantify economic impact C. quadricarinatus (Chapter 5) creel surveys were conducted during wet and dry season across the invasion range. The study showed that fish damage due to crayfish was limited to gillnets at the invasion core during the dry season and equated to the monetary loss of ~ US$ 21,000 per annum. In addition, gear damage and loss of time due to crayfish was experienced for various fishing gears but most prevalent at the invasion core and more so in dry season. Assessment of fishers’ awareness, knowledge and perception (Chapter 6) involved the use of social surveys administered at the invasion core. This component revealed that most of the respondents were aware of, but not knowledgeable about C. quadricarinatus. Respondents were not aware of any management information relating to C. quadricarinatus and consequently did not follow any management practices. The respondents were supportive of management interventions due to their perceived threat of C. quadricarinatus to the fishery. Age, education, and residence of respondents significantly influenced knowledge and perceptions of C. quadricarinatus. Findings from this study have important implications for the conservation of floodplain wetlands as it informs policy makers to put in place measures that address both overexploitation and aquatic invasive species dynamics to better facilitate sustainability of fisheries and conservation of biodiversity. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2024
- Full Text:
- Date Issued: 2024-10-11
Assessing the vulnerability of inland fisheries to human-induced perturbation in Lake Kariba fishery, Zambia
- Authors: Imikendu, Imbwae
- Date: 2024-10-11
- Subjects: Fisheries Kariba, Lake (Zambia and Zimbabwe) , Small-scale fisheries , Fishery policy , Biodiversity Kariba, Lake (Zambia and Zimbabwe) , Sustainable livelihood
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466725 , vital:76774 , DOI https://doi.org/10.21504/10962/466725
- Description: Inland fisheries play a critical role in providing nutrition, employment, and ensuring food security among vulnerable groups in Lake Kariba. However, their value is usually undermined in developmental plans, and their contribution to a broader economic development is often undervalued. Over the past two decades, inland fisheries have stagnated. Simultaneously, there have been wide reports of increased fishing effort and declining trends in commercially valuable fish species. This has resulted into a wide socio-economic and environmental problems in various fishing communities. Lake Kariba Zambia, exemplifies this sustainability challenge, where fisheries resources and livelihoods are interlinked. A systematic peer review paper on this topic was documented, published and used for analytical work, focusing on governance and how it affects the utilization of the fisheries resources for food security and biodiversity conservation. This study had four major objectives: (i) to identify threats to fisheries’ productivity in Lake Kariba; (ii) to understand the socio-economic and environmental conditions of small-scale fisheries in Lake Kariba; (iii) to determine adaptation strategies adopted by small-scale fishers in light of the changing socio-economic and environmental conditions in Lake Kariba; (iv) to determine how management of fisheries has to change in response to the wide socio-economic and environmental challenges in the region. Using Ostrom’s framework for analysing socio-ecological systems, various socioeconomic and environmental problems faced by fishing communities in Lake Kariba were examined to devise a sustainable fisheries management plan. The study employed explorative surveys, household questionnaires, key informant interviews, focus group discussions, observations, and a review of literature to elicit secondary data. A proportional quota sampling technique was used to draw a representative sample of 300 small-scale fishers and a typology was developed using a bivariate analysis. Chi-square was used to determine fishing effort over time. Using a curve fitting estimation regression test, a trend analysis in fish production for the past thirteen years (13) years was performed. Results did not show a significant decline in fish production over the past 13 years, yet experts and the fishers reported declining trends in valuable fish species. The finding of this study provides both practical and theoretical lessons that can enhance adaptive capacity and support sustainable livelihoods in the region. A fisheries sector policy is urgently required to guide governance process and coordinate a multi-sectoral perspective to fisheries management if socio-economic progression is to be attained. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Imikendu, Imbwae
- Date: 2024-10-11
- Subjects: Fisheries Kariba, Lake (Zambia and Zimbabwe) , Small-scale fisheries , Fishery policy , Biodiversity Kariba, Lake (Zambia and Zimbabwe) , Sustainable livelihood
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466725 , vital:76774 , DOI https://doi.org/10.21504/10962/466725
- Description: Inland fisheries play a critical role in providing nutrition, employment, and ensuring food security among vulnerable groups in Lake Kariba. However, their value is usually undermined in developmental plans, and their contribution to a broader economic development is often undervalued. Over the past two decades, inland fisheries have stagnated. Simultaneously, there have been wide reports of increased fishing effort and declining trends in commercially valuable fish species. This has resulted into a wide socio-economic and environmental problems in various fishing communities. Lake Kariba Zambia, exemplifies this sustainability challenge, where fisheries resources and livelihoods are interlinked. A systematic peer review paper on this topic was documented, published and used for analytical work, focusing on governance and how it affects the utilization of the fisheries resources for food security and biodiversity conservation. This study had four major objectives: (i) to identify threats to fisheries’ productivity in Lake Kariba; (ii) to understand the socio-economic and environmental conditions of small-scale fisheries in Lake Kariba; (iii) to determine adaptation strategies adopted by small-scale fishers in light of the changing socio-economic and environmental conditions in Lake Kariba; (iv) to determine how management of fisheries has to change in response to the wide socio-economic and environmental challenges in the region. Using Ostrom’s framework for analysing socio-ecological systems, various socioeconomic and environmental problems faced by fishing communities in Lake Kariba were examined to devise a sustainable fisheries management plan. The study employed explorative surveys, household questionnaires, key informant interviews, focus group discussions, observations, and a review of literature to elicit secondary data. A proportional quota sampling technique was used to draw a representative sample of 300 small-scale fishers and a typology was developed using a bivariate analysis. Chi-square was used to determine fishing effort over time. Using a curve fitting estimation regression test, a trend analysis in fish production for the past thirteen years (13) years was performed. Results did not show a significant decline in fish production over the past 13 years, yet experts and the fishers reported declining trends in valuable fish species. The finding of this study provides both practical and theoretical lessons that can enhance adaptive capacity and support sustainable livelihoods in the region. A fisheries sector policy is urgently required to guide governance process and coordinate a multi-sectoral perspective to fisheries management if socio-economic progression is to be attained. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2024
- Full Text:
- Date Issued: 2024-10-11
Assessment and mitigation of biosecurity risks associated with macroalgae inclusion in farmed abalone diets in South Africa
- Mwangudza, Petronilla Masika
- Authors: Mwangudza, Petronilla Masika
- Date: 2024-10-11
- Subjects: Biosecurity , Seaweed , Abalone culture South Africa , Abalones Feeding and feeds , Haliotis midae , High-throughput nucleotide sequencing
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466748 , vital:76775 , DOI https://doi.org/10.21504/10962/466748
- Description: The provision of biosecure diets for use in intensive aquaculture conditions requires attention, to reduce the risk of introducing potential pathogens to the farmed stock. Such introductions could lead to infections and disease outbreaks. Despite the benefits associated with macroalgae inclusion in abalone diets, several microbial hazard cases have been reported in the animal feed and human food industries. This has necessitated the application of biosecurity measures on fresh macroalgae to reduce or eliminate potential hazards and the risks of pathogen transfer to abalone stock when used as a feed or feed supplement. The present thesis assessed the efficacy of different processing treatments, including heat, ultra-violet irradiation (UVC), different pH levels, salinity concentrations, and povo-iodine on the inactivation of potential macroalgaetransmitted abalone pathogens. The effect of the processed macroalgae on the growth, health and gut microbial composition of abalone were also explored and compared with abalone fed non-processed diets. The efficacy of the different processing treatments was initially assessed on pure cultures of the test pathogens, which included a bacterium (Vibrio anguillarum), an oomycete (Halioticida noduliformans) and the bacteriophage lambda. Data from the initial assessments were then used to select the most optimal treatments for further assessment on the test pathogens inoculated in a macroalgae matrix, to simulate a more natural scenario. The viability of the three test pathogens following exposure to different processing treatments was assessed using culture methods. The results indicated that a combination of three treatments; disinfection using povo-iodine solution (5000 mg/L) for 20 min, oven drying 40 ℃ for 8.0 h and UVC treatment for 10 min rendered all the test pathogens non-culturable. Growth trials were conducted to assess the effect of the biosecure macroalgae Ecklonia maxima, Ulva lacinulata and Gracilaria gracilis on the growth performance of the abalone Haliotis midae. The macroalgae were subjected to the combination of three biosecurity processing treatments and experimental diets were then formulated to incorporate the macroalgae that had been subjected to the biosecurity processing treatments as well as macroalgae that were not. Growth parameters of the abalone after a 150-day feeding trial were compared between the biosecure and non-bioseeure macroalgae dietary treatments. Overall, the lowest growth was observed in the abalone fed with the control diet (AbfeedTM S34R) compared to all the macroalgae diets. However, no significant differences in abalone weight and shell length were recorded between the dietary treatments after the 150-day growth trial with an overall mean final weight (} standard error) of 56.55 } 0.78 g and a mean final length of 66.26 } 0.344 mm (RM-ANOVA: F(18,63) = 0.706; p = 0.792; : F(18,63) = 0.941; p = 0.535 respectively). Similarly, the biosecurity process method (biosecure vs. non-biosecure) did not have an impact on abalone weights and shell length (p > 0.05). Moreover, specific growth rate, length gain and condition factor of abalone did not differ between the biosecure and nonbiosecure dietary treatments with overall means (}standard error) of 0.27 } 0.01 % bw/d, 1.79 } 0.07 mm/month and 1.13 } 0.01, respectively (p > 0.05). Dietary macroalgae are known to contribute to the gut microflora of abalone. To determine if the biosecure process influenced this community complex, a next generation sequencing (NGS) approach was used to identify and compare the bacterial communities in abalone that were fed diets containing macroalgae that had been subjected to biosecurity treatment and those that were not. The NGS approach was also used to determine the gut microbiome profile of the abalone fed with a formulated diet supplemented with fresh U. lacinulata and G. gracilis to assess the potential modulatory effect seaweeds and their associated microbiota may have on the gut microbiome of H. midae. The bacterial alpha diversity did not differ significantly across all the diets at family, genus and species levels (p > 0.05). No significant differences in the microbiome composition were detected indicating little or no dissimilarities of the bacterial communities between the diets for all the biosecure and non-biosecure macroalgae diets. A similar core microbiome was also observed in the digestive tracts of abalone fed with the biosecure and non-biosecure diets. It was concluded that the biosecure process did not influence the natural microbiota of abalone that were fed dietary ingredients that were subjected to the process. The findings of this research have contributed to understanding the production of biosecure macroalgae formulated diets without compromising their benefits to the growth and health of farmed abalone. The combined treatment used in this study can be applied in the macroalgae and the feed industry to produce biosecure feeds. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Mwangudza, Petronilla Masika
- Date: 2024-10-11
- Subjects: Biosecurity , Seaweed , Abalone culture South Africa , Abalones Feeding and feeds , Haliotis midae , High-throughput nucleotide sequencing
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466748 , vital:76775 , DOI https://doi.org/10.21504/10962/466748
- Description: The provision of biosecure diets for use in intensive aquaculture conditions requires attention, to reduce the risk of introducing potential pathogens to the farmed stock. Such introductions could lead to infections and disease outbreaks. Despite the benefits associated with macroalgae inclusion in abalone diets, several microbial hazard cases have been reported in the animal feed and human food industries. This has necessitated the application of biosecurity measures on fresh macroalgae to reduce or eliminate potential hazards and the risks of pathogen transfer to abalone stock when used as a feed or feed supplement. The present thesis assessed the efficacy of different processing treatments, including heat, ultra-violet irradiation (UVC), different pH levels, salinity concentrations, and povo-iodine on the inactivation of potential macroalgaetransmitted abalone pathogens. The effect of the processed macroalgae on the growth, health and gut microbial composition of abalone were also explored and compared with abalone fed non-processed diets. The efficacy of the different processing treatments was initially assessed on pure cultures of the test pathogens, which included a bacterium (Vibrio anguillarum), an oomycete (Halioticida noduliformans) and the bacteriophage lambda. Data from the initial assessments were then used to select the most optimal treatments for further assessment on the test pathogens inoculated in a macroalgae matrix, to simulate a more natural scenario. The viability of the three test pathogens following exposure to different processing treatments was assessed using culture methods. The results indicated that a combination of three treatments; disinfection using povo-iodine solution (5000 mg/L) for 20 min, oven drying 40 ℃ for 8.0 h and UVC treatment for 10 min rendered all the test pathogens non-culturable. Growth trials were conducted to assess the effect of the biosecure macroalgae Ecklonia maxima, Ulva lacinulata and Gracilaria gracilis on the growth performance of the abalone Haliotis midae. The macroalgae were subjected to the combination of three biosecurity processing treatments and experimental diets were then formulated to incorporate the macroalgae that had been subjected to the biosecurity processing treatments as well as macroalgae that were not. Growth parameters of the abalone after a 150-day feeding trial were compared between the biosecure and non-bioseeure macroalgae dietary treatments. Overall, the lowest growth was observed in the abalone fed with the control diet (AbfeedTM S34R) compared to all the macroalgae diets. However, no significant differences in abalone weight and shell length were recorded between the dietary treatments after the 150-day growth trial with an overall mean final weight (} standard error) of 56.55 } 0.78 g and a mean final length of 66.26 } 0.344 mm (RM-ANOVA: F(18,63) = 0.706; p = 0.792; : F(18,63) = 0.941; p = 0.535 respectively). Similarly, the biosecurity process method (biosecure vs. non-biosecure) did not have an impact on abalone weights and shell length (p > 0.05). Moreover, specific growth rate, length gain and condition factor of abalone did not differ between the biosecure and nonbiosecure dietary treatments with overall means (}standard error) of 0.27 } 0.01 % bw/d, 1.79 } 0.07 mm/month and 1.13 } 0.01, respectively (p > 0.05). Dietary macroalgae are known to contribute to the gut microflora of abalone. To determine if the biosecure process influenced this community complex, a next generation sequencing (NGS) approach was used to identify and compare the bacterial communities in abalone that were fed diets containing macroalgae that had been subjected to biosecurity treatment and those that were not. The NGS approach was also used to determine the gut microbiome profile of the abalone fed with a formulated diet supplemented with fresh U. lacinulata and G. gracilis to assess the potential modulatory effect seaweeds and their associated microbiota may have on the gut microbiome of H. midae. The bacterial alpha diversity did not differ significantly across all the diets at family, genus and species levels (p > 0.05). No significant differences in the microbiome composition were detected indicating little or no dissimilarities of the bacterial communities between the diets for all the biosecure and non-biosecure macroalgae diets. A similar core microbiome was also observed in the digestive tracts of abalone fed with the biosecure and non-biosecure diets. It was concluded that the biosecure process did not influence the natural microbiota of abalone that were fed dietary ingredients that were subjected to the process. The findings of this research have contributed to understanding the production of biosecure macroalgae formulated diets without compromising their benefits to the growth and health of farmed abalone. The combined treatment used in this study can be applied in the macroalgae and the feed industry to produce biosecure feeds. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2024
- Full Text:
- Date Issued: 2024-10-11